Released just a few months ago, the Darmoshark M3 has quickly garnered attention for its outstanding value proposition. Priced at the same $49.99, the M3S Varun picks right up where the M3 left off, and even ups the ante in terms of feature set: On top of a regular USB full-speed wireless dongle, which allows for a polling rate of up to 1000 Hz, the M3S Varun also comes with a USB high-speed dongle, enabling true 2000 Hz polling. And while the execution isn't flawless, the M3S Varun likewise ends up providing excellent value for money.

When it comes to the shape, the M3S Varun is very similar to the M3, yet notably different. Essentially, M3S Varun is a uniformly scaled-down M3, with the exception of the hump, which is located more towards the back, radically altering how the mouse feels in-hand in the process. Due to its smaller size, at 55 g, the M3S Varun ends up marginally lighter than the M3, despite featuring a 500 mAh battery once again. In terms of general build quality, I have little to complain about on my unit: There is no rattle when shaking, no creaking or flexing of the shell when applying lateral force, and actuating the side buttons by pressing below them is impossible regardless of force. Considering that the M3S Varun doesn't resort to holes or an open bottom for weight saving, it therefore compares favorably to mice such as the Pulsar X2 or LAMZU Atlantis Mini that do resort to an open bottom, yet don't manage to be much lighter. The feet are very similar to that of the M3, made of pure PTFE, and glide well, and a replacement set is included in the box, coupled with a set of grip tape, which is remarkable considering the price point.

For the main buttons, Darmoshark has opted for TTC Gold switches on the M3S Varun, which previously already had seen use on the M3 4K. Button response is pleasing, but due to moderate pre-travel, not quite as snappy as it could be. The buttons are firm though, as lateral movement is quite low even when provoked. TTC switches are likewise used for the side buttons, and while the forward button fares pretty well, the back button suffers from significant pre-travel, along with uneven actuation, both of which has it feel a bit mushy. For the scroll wheel, TTC's nearly ubiquitous yellow ("Gold") encoder is used, which usually produces quite a bit of noise when scrolling, but scores with nice tactility. This doesn't always apply, however, as I've found the scrolling on the Waizowl OGM Pro to be lacking in the tactility department, which applies to the M3S Varun as well, albeit to a lesser degree. In addition, the scroll wheel on my M3S Varun also emits a rather irritating creaking noise when scrolling up, which I haven't seen on this encoder before. Whether this is just a QC failure or indicative of poor binning from Darmoshark, I do not know, but it does strike me as odd how a single encoder model can display such vastly different characteristics.

As mentioned above, the M3S Varun comes with two different dongles, which not only look different but also perform differently. In regard to CPI deviation or general tracking, there is nothing between the two: Deviation is minimal, general tracking fine regardless of whether MotionSync is enabled or not, and the impact on motion delay caused by MotionSync is likewise the same, namely roughly half of the set interval, i.e., 0.5 ms at 1000 Hz. Being a USB full-speed device, the smaller dongle is restricted to 1000 Hz, at which polling rate a motion delay differential of around 1 ms is achieved without MotionSync. The larger dongle is a USB high-speed device and allows for up to 2000 Hz, but contrary to what one would be inclined to believe, latency doesn't benefit from this. In fact, I've often found motion delay to be closer to 2 ms, with some highs and lows to 1 and 3 ms, respectively. Motion delay is far from consistent, and this also applies to the other polling rates when using the high-speed dongle. In an apples-to-applies comparison at 1000 Hz, the full-speed dongle is more consistent and has lower motion delay on average, which is the opposite of how it should be. I do not know what could be causing this, though I did notice what I've previously called "shift behavior," whereby motion delay is randomly increased at some point during a motion, and which has been present on the M3 as well, for instance, to be particularly pronounced on the high-speed dongle, so this may be related. In terms of polling, the odd outlier aside, 2000 Hz is largely stable, but somewhat curiously, 125 and 500 Hz aren't stable on the high-speed dongle, whereas on the full-speed one, they are. The differences extend to click latency, too. With both dongles set to 1000 Hz, the full-speed dongle consistently beats the high-speed dongle, as the full-speed dongle averages 2.0 ms as opposed to 2.5 ms on the high-speed one with debounce time set to 0 ms, for instance, and one has to increase polling rate to 2000 Hz to see the high-speed dongle come out on top, although only at a debounce time of 0 ms. At a debounce time of 1 ms, click latency is 2.9 ms on the full-speed dongle and 4.9 ms on the high-speed dongle, which is oddly random and virtually inexplicable. Another thing to note is that certain debounce time settings have much higher standard deviation than others, both compared to other values on the same type of dongle or the other one. As with other mice using defer-type debouncing, slam-clicking at lower debounce time settings (0 or 1 ms) is expected and unavoidable, requiring one to increase debounce time to get rid of it if so desired.

In short, it is all a bit messy and inconsistent, but the bottom line is quite clear: 2000 Hz provides no latency benefit, and if anything, it ends up lagging behind competitors from years ago running at 1000 Hz. 2000 Hz does, however, cut down big time on battery life, so there is really no reason to use 2000 Hz or the high-speed dongle at all. Speaking of battery life, Darmoshark cites 80 hours at 1000 Hz, which is a reasonable estimate considering the battery capacity. The battery life indicator within the software isn't much of a help for gauging anything, as during my testing, the value essentially changed at random, and eventually got stuck at 100%. For what it's worth, the Telink TLSR8273 MCU used on the M3S Varun provides Bluetooth support, which can help extend battery life even beyond those 80 hours, if we are to believe this figure is accurate in the first place.

Overall, while the M3S Varun isn't perfect, one has to put things into perspective. Even though 2000 Hz is essentially useless, one still gets a well-performing 1000 Hz mouse for $49.99 on Mechkeys.com, complete with Bluetooth functionality and sets of replacement feet and grip tape thrown into the box as well. All in all, the M3S Varun isn't a worse package than the M3, though for those who were simply hoping for a smaller M3, the M3S Varun doesn't meet that expectation. And as always with a domestic Chinese brand such as Darmoshark, buyers need to be aware that support or warranty may be limited for those not based in China. For those willing to take this risk, the M3S Varun is a highly affordable and worthwhile option, earning our Recommended and Budget awards.