Earlier this year, the Burst Pro Air (see here for our review) greatly missed the mark, being riddled with technical issues: severe polling instability, variable motion delay, slow charging, no wireless extender, and buggy software made for an unappealing product. Unfortunately, instead of improving on these issues, ROCCAT effectively doubles down on them with the Kone XP Air.

Once again, sensor and wireless performance are the core issues. For this review, I've based my testing on the latest firmware supposed to address these issues, yet performance continues to be subpar. As with the Burst Pro Air, polling is highly unstable, especially in wireless (2.4 GHz) operation and in conjunction with the RGB lighting. Thankfully, ROCCAT by now has added the option to turn off the RGB lighting entirely, and with illumination disabled, polling stability approaches acceptable levels in wired mode at least, but for all intents and purposes, stable polling is still a very rare commodity when using the Kone XP Air. Not to mention, nobody would buy an RGB-heavy wireless mouse to only use it wired and without RGB, so this is essentially meaningless. While general tracking still is negatively affected by the polling instability, motion delay and click latency at least aren't any longer, though the wireless delay is surprisingly high on the Kone XP Air. I've measured a wireless motion delay of roughly 3 ms at a minimum, which is considerably worse than what the Burst Pro Air or Kone Pro Air were able to muster. The higher delay extends to click latency, too, as wireless click latency is 2.5 ms higher than wired. At 3.6 ms in total, click latency in wireless (2.4 GHz) operation is still very competitive, but previous ROCCAT releases did even better in this regard. Most curiously, the Kone XP Air also suffers from very high CPI deviation, which also wasn't a thing on previous ROCCAT mice. The deviation is quite easily adjusted for, but there's another issue linked to this, which brings me to Swarm, ROCCAT's staple software.

Swarm has been around for quite a few years by now, and is clearly showing its age. Resource usage has gone up over time, and during testing, I've encountered more bugs than ever. For instance, the LED sleep timer setting is supposed to govern after how much idle time the mouse goes into sleep. Yet, the setting is only present within Swarm if the mouse is plugged in, where this setting doesn't even apply. And even then, the setting appears to be broken altogether, and never actually applies anyway. Furthermore, the Kone XP Air has a certain tendency to reset itself to its default settings, which includes CPI levels. More often than not, I've found myself quite surprised that CPI had suddenly changed or the RGB lighting turned back on. Only after opening Swarm once did the mouse remember what I've set it to previously. The "energy saving" option reacts very slowly to where it is all but useless, and "slow" is a perpetual state when interacting with Swarm, as every little setting change takes several seconds to apply. Of course, the mundane act of updating the firmware still takes upwards of five minutes on the Kone XP Air. Finally, from what I can tell, button rebinding is entirely dysfunctional. Masochists may find joy in dealing with Swarm, but I don't. I don't know how many of these bugs were introduced with the latest firmware, but either way, unleashing something this buggy upon unsuspecting customers is inexcusable. For the record, ROCCAT has not been able to replicate the issues related to CPI deviation and 2 ms polls at 1000 Hz in wireless (2.4 GHz) operation, so it's possible my unit has been faulty in this regard.

At 98 g, the Kone XP Air weighs the same as the wired Kone XP, which is actually a respectable achievement, given that a 450 mAh battery is used. Build quality is good on my unit, as creaking and flexing are minimal, and while actuating the side buttons by squeezing the sides is possible, doing so requires moderate force and only affects the rear button, so I don't think this is worth criticizing. Compared to the Kone XP, the side buttons in particular are improved, as pre and post-travel are noticeably lower, and the buttons feel more stable as a whole. The main buttons are unchanged, and, as is the nature of optical switches, don't feel quite as snappy as mechanical switches such as Kailh GM 8.0. The right main button in particular suffers from a rather dull and muted response, accompanied by significant post-travel. The scroll wheel fares better in comparison, scoring with great tactility, though noise levels are higher than I'd want them to be. The scroll wheel click, however, is ridiculously stiff, which I've found to be inherent to the design upon disassembly. Essentially, one is pressing down on a whole lot of plastic, which greatly adds to the necessary force required for pressing down the switch plunger. Outside of a complete redesign, there is little ROCCAT or anyone else could do about this. The tilting wheel at least works just as well as it did on the wired Kone XP. The feet are unchanged compared to the Kone XP and still glide as excellent as ever.

Unlike the Burst Pro Air, the Kone XP Air does have a wireless extender included, albeit as part of a charging dock. The charging dock is certainly more convenient than having to plug the mouse in, but in terms of charging speed, neither method is particularly fast. Battery life is a bit of a mystery on the Kone XP Air. ROCCAT cites more than 100 hours, but this only applies when using Bluetooth and no illumination. In 2.4 GHz mode and with illumination fully enabled, I'd expect battery life to be in the range of 30 hours, although I have no way of verifying this since the battery indicator in the software is far from reliable or accurate. Playing while charging when using the cable is perfectly possible at least, as the cable is decently flexible.

Overall, I'm simply baffled by the Kone XP Air. Despite being priced like a premium product, the performance to match this pricing is nowhere to be found. There is also something to be said about how barebones everything is. How come there is a set of replacement feet included on the $89.99 Kone XP, but not on the $169.99 Kone XP Air? As a comedic effort, I can appreciate ROCCAT charging $169.99 for the Kone XP Air, but even at half of that, I'd steer clear of this mouse. If ROCCAT finds a way to address the performance issues in a firmware update and at a heavy discount, the Kone XP Air may become worthwhile at some point, but as of now, the Kone XP is inarguably by far the better buy.