Mionix Castor Optical Gaming Mouse Review

By Tom Jaskulka

Manufacturer: Mionix AB
Product Name: Castor Optical Gaming Mouse
Model Number: MNX-01-25001-G
UPC: 851260002002
Price As Tested: $69.99 (Amazon | Mionix EU Store)

Full Disclosure: The product sample used in this article has been provided by Mionix.

Mionix, the Swedish manufacturer of a range of gaming peripherals, has a new star in their lineup: the Castor Optical Gaming Mouse. Designed to retain the ergonomic grip of the Naos while still accommodating the three main grip styles (claw/palm/fingertip), the Castor is poised to be a comfortable option for a wide variety of users. Coated in their customary soft-touch rubber coating, the smooth curves and Aurora multi-color lighting identify this newest addition as a member of the Mionix family. Benchmark Reviews was given a chance to take a closer look at the Mionix Castor – will the tales of exquisite craftsmanship, 10,000 DPI optical sensors, zero acceleration and a grip that appeals to everyone… appeal to everyone? Let’s take a look.

Note: Features and Specifications Courtesy Mionex

Setting a new standard in ergonomic comfort and gaming performance, Mionix today announced the CASTOR, the latest entry in their stellar lineup of premium gaming mice. Named for one of the brightest stars in the night sky, the 6-button, multi-color optical CASTOR mouse is crafted especially for right-handed gamers with dedicated ring and pinkie finger grooves and enhanced rubber grip, and features the outstanding technical performance that has made Mionix a cult favorite worldwide.

Right from the onset, it’s clear that the Castor has a slightly new direction. While the Mionix boxes have always been pretty simple, the Castor ratchets it up a notch.

The whole thing folds out to display the molded shells that protect the Castor during shipping. A message from the CEO is prominently displayed in the middle. This won’t be the last time you see the word craftsmanship. Sandwiched between two formed shells, the Castor sits cradled in a removable insert with the two meter cable tucked underneath.

Other than the Castor itself, Mionix includes a Quick Start Guide and Warranty Information guide in the box. A set of stickers complete the package.

The Mionix Castor is an average-sized gaming mouse, with a right-hand oriented grip. It’s not quite five inches long (and just over two and a half inches wide – 122.46mm x 70.42mm), which is just a little smaller than something like a DeathAdder. The overall shell shape should support a wide range of hand sizes. A single DPI toggle button (which is programmable like the others) sits just behind the scroll wheel.

The bottom of this mouse is devoid of the serial/model/FCC/etc. markings common to many gaming mice, fitting nicely with Mionix’s clean, efficient approach to design. Two large teflon pads bracket the 10,000 DPI optical sensor (a Pixart PMW-3310) in the center of the Castor, with the Mionix logo and another craftsmanship comment the only other features in view.

The left side of the Castor is dominated by the first major cosmetic change to a Mionix mouse yet – a rubber grip pad. The texture isn’t extreme, and does a good job overall keeping traction high.

The right side is featureless except for the subtle ring and pinky finger grooves. The mouse itself isn’t very tall (just over an inch and a half / 40.16mm), making it fit right in with most other mice.

The scroll wheel is pretty standard fare for Mionix, although I think I’ve been spoiled by Roccat’s “Titan” scroll wheels lately. The version here seems to do its job well enough even if a little more tactile feedback would be welcome. There is virtually zero horizontal play on the scroll wheel itself; while horizontal scrolling isn’t a feature on most gaming mice, the middle click / scroll wheel button on many models tend to cause a bit of a wiggle – as we’ll see later, Mionix takes a slightly different approach that lends a bit of horizontal stability to their wheel.

The unique grip shape of the Castor is what claims to accommodate palm, claw, and fingertip grip users. At first touch, it seems Mionix is on the right track – as with many mice though, a marathon gaming session can highlight comfort issues that may not be apparent with the first few minutes of use. Does the Castor live up to the claims of “one grip comfort” for all users? Let’s take a detailed look at some more features, then get to the testing.

We’ll compare the Castor to another popular gaming mouse in the next few pages, but first let’s take a closer look at some of the features of Mionix’s newest offering.

The grip shape is arguably the selling point of the Castor. It’s tough to highlight the smooth curves all over the shell of this mouse, but I think Mionix did a great job developing their “hybrid” grip. As with any mouse, you’d want to try one out at a retail store first if you’re overly concerned with ergonomics, but the Castor ranks easily in the top five of “most comfortable mice” I’ve personally used.

The left side forms a slightly-indented smooth curve for your thumb, with the two side buttons sitting along a prominent ridge just above where your thumb would naturally rest. I struggled to differentiate these two buttons by feel – perhaps a more distinct button shape or separation would help. Towards the end of the few weeks I spent testing the Castor, I could easily hit “Back” (the rear-most button) without fear of any accidental Forward presses, but since Back was a bit higher on the ridgeline it was almost impossible to hit that forward button without also triggering a Forward button press. I liked the overall grip shape of the Castor, but the stiffness of these buttons (or shape/size as well) might need some attention to prevent mis-clicks.

The textured side grip is a new addition to Mionix’s lineup, as they generally covered their entire mice in that exquisite 4-layer rubber coating (if you’re sad that Razer switched to hard-textured plastic instead of the rubber coatings of yesteryear, Mionix has always done this type of coating as good – or better, really – than Razer, in my very own humble opinion). I’m not sure if circles were the best shape for grip, but it does feel pretty good on your thumb regardless.

A single DPI switch is the only addition to the otherwise-standard three main/two side button arrangement. It’s a little odd that the Castor only sports six buttons when many mice in this price range (and every other Mionix model) contain at least seven or more, but more doesn’t always mean better. The number of buttons isn’t as much of a concern to me personally – I’ve always been more interested in the button feel of the ones that are there, rather than the total amount that can be crammed on a mouse.

I already mentioned my frustrations with the side buttons – how about the main mouse buttons? I much prefer stiff, tactile clicks on main mouse buttons, and I was looking forward to the Castor given my experience with a Mionix Naos 8200 (which had great button-feel). My first reaction was disappointment – the click action on the Castor felt a little soft and mushy. I decided to open up the Castor to see what type of switches were inside…

…where I found the exact same (Omron D2FC-F-7N) switches used in the Naos!? To be clear, these are some of my favorite/preferred switches in mice with superb tactile response. Perhaps they just needed some breaking in, or the shell shape (or even the rubber coating?) contributed to the slightly different feel, but the Castor never felt quite the same to me as the Naos. After the first week, whether it was just perception or familiarity creeping in (or it really did require a “break-in” period), the Castor livened up a bit. The side buttons could still use a little work – they weren’t Omron switches like the main mouse buttons – but I ended up being satisfied overall with the button feel after two weeks. As a side note, the above photo nicely illustrates how Mionix avoids any horizontal play in their scroll wheels – that barrel on the wheel is easily five times the diameter of most scroll wheel support posts!

Mionix’s driver software is pretty standard, which will allow most users to become quickly acquainted with the different settings of the Castor. The main tabs across the top list the different sections, with the currently active profile listed right below. All of the changes are saved to the Castor’s on-board memory once Apply or Ok are clicked. Some other manufacturers will update any changed settings the moment they are adjusted, but I don’t mind this approach – I generally like to make changes and “finalize” them at the very end.

The first tab is the Mouse Settings tab. Button bindings are set here, with all six of the Castor’s buttons available for mapping. Polling rate, acceleration, double click and scroll speed are set here as well.

The Sensor Performance tab should be pretty self-explanatory. DPI is adjustable in 50-dpi steps, from 50 to 10,000 dots per inch. Three steps can be set, with the mouse’s on-board memory saving your last-used DPI step (no need to set a default). Angle Snapping and Tuning were turned off by default, and can be activated here if desired. The Lift Distance was set a little high, but it was a simple slide to the lowest setting.

The Castor also uses Mionix’s S.Q.A.T. feature, which will provide some feedback on the sensor’s ability to track your current mousing surface. Without knowing more about how this feature arrives at its scores (a 100 represents “no data loss”), it’s hard to compare different surfaces – although it seems hard pads perform better than cloth/soft mouse pads. A Razer Destructor 2, Func Surface 1030r2 (smooth side) and Steelseries 4HD all scored 100%, while a Razer Goliathus (speed) scored a 60%, a Steelseries QHD+ scored a 70% and two Roccat Sense cloth pads (Desert Strike and Naval Storm editions) scored a 40%. Interestingly enough, I didn’t notice any skips or jitters on any of the aforementioned surfaces; it seems obvious a hard pad would be the surface of choice for enthusiasts that want the maximum available performance but you’d be hard pressed to feel much of a difference.

Color Settings contains all of the options for Mionix’s Aurora lighting which is standard on all of their mice. There are two zones on the Castor which can be set individually (or turned off as desired). A Color Shift feature fades through a rainbow of colors, or solid colors can be used in the Solid, Blinking, Pulsating or Breathing modes.

A range of colors displays nicely on the Castor – it doesn’t struggle with the less common colors like yellow, orange, teal and pink like some other multi-color options. Reds are a deep red, blues are vivid; greens are somewhat soft but more of a true green. Mionix has always featured multi-color lighting on their mice, but once you see some new RGBY LED-lit mice (like the Roccat Tyon) the previously-standard RGB systems look a little less vivid. I think the lighting system on the Castor fits nicely with the overall subtle style of Mionix’s peripherals in general though, and while the LEDs may not be as piercingly bright or vivid as some newer systems that might be just fine (I’m personally a fan of blinky lights and colors – I know these options don’t appeal to everyone, and the Castor looks more sophisticated than many gaming peripherals with the lights on or off).

The macro editor is somewhat rudimentary, but contains all of the necessary features for programming custom macros. Mouse events can be included in a macro which is always nice to see (not every device allows this). Delays can be recorded as you program the macro, or can be inserted/edited afterwards. Individual events can be edited or deleted without disrupting the entire macro.

Finally, the Support tab lists a few helpful links to keep the Castor in optimum condition. The current software/firmware versions are listed in the lower right. A one year warranty (US – two years in the UK) covers the Castor from any manufacturer defects.

While I spent a fair amount of time gaming with the Castor, I’ve always found it helpful to compare physical shapes to other popular (and maybe some not-so-popular) mice. Since ergonomics and comfort are some of the primary reasons to select certain mice over others, it helps to place a few side by side and just see which ones feel comfortable. Grip shapes are exceedingly difficult to objectively test, as they are almost purely personal preference. It’s pretty fair to say you’ll spend most (if not all) of your time gaming at a computer interacting with these peripherals, so to find one that fits your hand ranks pretty high. If possible, try out a mouse you’re interested in at a retail store or a friend’s place – after some time, you’ll be able to look at a mouse and determine with a decent amount of accuracy if it will fit your hand at not. For those users, hopefully the following section will be useful.

The first time I saw a photo for the Castor, I immediately thought of the ever-popular Death Adder. Both use optical sensors, are praised for their ergonomics and contain a similar number of buttons. The Castor a slightly different sensor (PMW3310) than the Razer DeathAdder Chroma (s3989) pictured here, but for this section we’ll primarily be looking at the actual physical shapes and their similarities/differences.

The DeathAdder is primarily a palm-grip style mouse, and contains one of the higher/sharper arches on the market. The Castor is a bit more subdued, but still feels as comfortable (if not more so, especially for those with smaller hands) than the DeathAdder. The lower arch of the Castor accommodates the other grip styles (claw/fingertip) better than the DeathAdder specifically.

The side profiles of the two mice follow a similar theme that are markedly different in practice. Razer choose to make the Mouse4/Mouse5 buttons quite prominent – they’re easy to differentiate, with the textured thumb grip almost an afterthought (indeed, it was non-existant on the early models of the DeathAdder). The textured thumb grip on the Castor is much more extensive; again lending credence to the focus on accommodating multiple grip styles. However, the side buttons seem to suffer a bit because of it. In practice, even after 30+ hours of becoming familiar with the Castor, I could never seem to hit the forward button independently of the rearward.
The Castor is also flatter than the Adder, without the egg-shaped slope trailing off to the right. While somewhat similar in size, they feel very different in-hand. The DeathAdder seems to “fill” your hand, while the Castor feels more like gripping a baseball – the finger grooves are pretty subtle, and the overall shape is very comfortable. More so than the Adder, I would say, since it seems to accommodate personal preference rather than force your hand into a particular shape.
I spent about three weeks of as much working, gaming, editing and all-purpose computing that I could fit in. Mice are highly subjective, and only you can really know what you’re looking for in a peripheral. That being said there are a few areas were some observations can be useful.

First up, sensor performance.

While there are lot of different ways to test sensors, the raw data isn’t necessarily terribly useful to most – personally, I think a device designed to connect a human to a computer should rely more on the human-perception side of the equation rather than the data itself anyway. After all, it’s really the interpretation of the difference of frames that causes cursor movement – interpretation that varies from sensor to sensor (indeed, even from model to model of the same sensor, depending on the manufacturer’s implementation). So, sometimes the simplest can be the most useful: the ever-popular “Paint” test. Drawing a few lines can provide a bit of insight to a mouse sensor – does it accurately track movements? Does it try to “guess” (prediction) where you’re trying to move the mouse, or does it just report the exact location and movement? The Castor can utilize acceleration and prediction, but they are turned off by default – and it appears that they are quite non-existent when turned off, as the marketing materials claim. Even slight deviations from a straight line are not lost to the PMW 3310 IR-LED sensor used in the Castor. I’d be pretty confident assuming the Mionix Castor is providing as direct of a link to cursor movement as possible.

The polling rate is set to 1000 Hz by default, and the Castor has no trouble reporting at that rate.

 

The hybrid “one-size-fits-all” grip remained comfortable even over multiple-hour gaming sessions. The shape seemed to lend itself naturally to accuracy – I felt more accurate using the Castor than some other mice. No doubt the sensor had a part to play there, but I couldn’t help but feel the ergonomics themselves assisted in keeping the mouse cursor exactly where I wanted. I didn’t experience any cramping or other pain when using the Castor, and the smooth curves overall didn’t reveal any uncomfortable pressure points in the body of the mouse. If nothing else, I can certainly say the Castor was comfortable to use – I use a slightly-strange combination of palm and claw grips, and the Castor accommodated my hands without an issue.

Overall, I was a little torn in my opinion of the Mionix Castor. To be honest, I didn’t like it at first. It wasn’t the feel – it felt great from the moment I removed it from its box. The surfaces were silky smooth and very pleasant to the touch, and the grip shape was very comfortable. I wanted to like the Castor, as I’ve been very impressed with Mionix’s mice in the past (I purchased a Naos specifically to compare to a Func MS-3 – both very comfortable, ergonomic palm-grip mice). The Naos had the same smooth curves and oh-so-pleasant rubber coating, but the button action and scroll wheel felt much more crisp – maybe it’s just nostalgia, as the Castor uses the same Omron D2FC-F-7N switches, but the Castor didn’t have that same crisp tactile feel. It turned me off at first, since that’s one of the primary things I personally look for in a mouse. Still, as time went on, I couldn’t deny that the Castor was a very comfortable mouse with near-flawless performance. It might not make my own personal list of preferred mice, but I’d have no trouble recommending it to friends looking for a comfortable, well-performing ergonomic option.

I can’t complain about the performance of the Castor whatsoever. Even though some surfaces didn’t receive S.Q.A.T. ratings as high as others, I didn’t experience any skipping or jittering with any mousing surface I tried. I generally use DPI settings around 800, and at that setting I couldn’t detect any acceleration or erratic cursor movement at any time. The polling rate held steady throughout. The PMW-3310 sensor performed admirably in the Castor, and given its near-universal acclaim across the enthusiast arena this doesn’t come as much of a surprise. The grip shape lent itself well to accuracy – I never felt like I had to fight the mouse itself to get the cursor to move where I wanted.

I also quite like the appearance of the Castor. Soft-touch finishes just look better in my opinion, as subjective as that may be. The Castor doesn’t seem overly busy like some gaming devices tend to be, and every feature down to the logo seems to reflect a simpler, more efficient (dare I say sophisticated?) approach to design. Even though the curves used throughout are quite complex, it just lends an air of “silkiness” to the whole thing.

The construction of the Castor is certainly adequate for it’s price range. It doesn’t feel cheap in hand, at least not when you first touch it. The four-layer rubber coating is – I’ll say it again – exquisite (as it is on all of Mionix’s peripherals). There’s just something about painted soft-touch finishes that feels so much better than the textured/sandpaper plastic surfaces that are on most mice nowadays. However, I’m not sure if the Castor lives up to the focus on Craftsmanship – at least not as much as Mionix may like. The side buttons need Omron switches too, in my opinion (both to prevent misclicks and lend a more crisp feel to the entire device), and the scroll wheel detents could be a little less vague as well. The construction itself is quite good (as I found out when taking the Castor apart – nary a burr or untidy solder point anywhere, even in areas that would never be visible!), but these other aspects could use some attention to really solidify that commitment to craftsmanship. It didn’t help that some of the matte paint on the side buttons wore off the first few hours I used the Castor, but I’m willing to chalk that up to pre-production/sample issues (generally this indicates more of a surface/prep issue with the paint bonding, which probably wouldn’t occur -at least not consistently- with production in full swing).

I found the functionality of the Castor to be adequate for the price range – all of the main features are there: programmable buttons, on-board memory to store profiles, a simple yet powerful macro editor and multi-color LED lighting. I would have liked a few more buttons to work with, but the overall grip shape and sensor performance made up for any area that may have been lacking. After all, one of the primary selling points of the Castor, in my opinion, is that ergonomic grip – and that it delivers.

Which leads us to the final discussion – the value question. Multi-color lighting, quality construction, top of the line sensor performance and adaptable ergonomics are features pretty common to the $60-$90 range of gaming devices, and the Mionix Castor falls just to the left of middle in that range. While it is just starting to become available online, the Castor will be sellling for an estimated retail price of $69.99 (Amazon | Mionix EU Store). It’s a fair price for the features, but it also lies smack-dab in the middle of some very popular options. If you’re a fan of Mionix and find the Castor’s grip to be comfortable, it’s a pretty easy choice – other than that, I’m not sure the Castor brings anything to the table that other mice can’t do at this price point.

In the end, while it doesn’t introduce any gimmicks or mind-blowing features, the Mionix Castor is a very solid offering that gets to the core of a computer mouse – it puts the cursor exactly where you expect, without so much as a skip or jitter. It does so while accommodating multiple grip styles surprisingly comfortably, and has a decent, straightforward driver suite to boot. If possible, see if you can get your hands on one – if you find it as comfortable as I did and just want something that allows you to game as comfortably and accurately as possible, I wouldn’t have a problem recommending the Castor to you.

+ Soft-touch rubber finish
+ No-nonsense, easy to use driver
+ Ergonomic grip really delivers comfort
+ Multi-color LEDs standard
+ On-board memory to store profiles
+ High-end optical sensor with near flawless performance
+ Scroll wheel very solid…

– …except while scrolling rapidly
– Button feel seems a bit soft
– Feels like it needs one more button (dpi up AND down?)

• Performance: 10.0
• Appearance: 9.00
• Construction: 7.00
• Functionality: 7.50
• Value: 8.00

Recommended: Benchmark Reviews Seal of Approval.

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