Much like on the Corsair M65 RGB Ultra Wireless, button quality on the M65 RGB Ultra varies depending on which batch the unit in question is from. The initial launch batch was outfitted with Omron D2FP-FN (China) switches, which proved disastrous on my sample of the M65 RGB Ultra Wireless, but fared better on the M65 RGB Ultra. If one is lucky and receives a good unit, these switches can be serviceable, providing a very sharp and defined button response, but the odds of that happening aren't as high as they should be. Hence, Corsair has switched to TTC optical switches for later batches, which lack the sharpness of the Omron switches, but are more uniform and consistent. Whereas the side buttons were horrendous on the initial launch batch of the M65 RGB Ultra Wireless, the M65 RGB Ultra didn't have this issue. Irrespective of the batch, the side buttons are decent at least, with the forward button being the better of the two, whereas the back button suffers from noticeable pre and post-travel, along with uneven actuation. The scroll wheel is good: scrolling up in particular is noisy, but tactility is good, resulting in pleasing and controlled scrolling.

Where the M65 RGB Ultra truly shines is performance. Corsair's PAW3393 sensor already proved to be highly capable on the Sabre RGB Pro Wireless and M65 RGB Ultra Wireless, but on the M65 RGB Ultra it shows what it is truly capable of. CPI deviation is very low, there is no smoothing across the entire CPI range, resulting in very low motion delay, polling is rock-solid across the board, and MotionSync ensures excellent tracking. And while performance at 2000, 4000, and 8000 Hz already was very good on the Sabre RGB Pro, the M65 RGB Ultra manages to surpass that, reaching near-parity with the Razer Viper 8K, which is commonly regarded as the gold standard for 8000 Hz polling. The same goes for click latency: Owing to 8000 Hz polling, the M65 RGB Ultra reaches parity with the Viper 8K, provided debouncing is disabled. Since the M65 RGB Ultra utilizes optical switches, disabling debouncing does not result in inadvertent double-clicking, but slam-clicking is possible, which describes unintentional button actuation upon resetting the mouse. With debouncing enabled, click latency is a bit higher, but still competitive. In short, when it comes to performance, faulting the M65 RGB Ultra is nearly impossible.

8000 Hz has higher standards when it comes to cable shielding than 1000 Hz does, which is why the cable on the M65 RGB Ultra isn't the most flexible. However, it is a fair bit more flexible than the Viper 8K cable, and generally flexible enough to be considered usable. As for build quality, I have nothing to complain about on my unit: No rattle when shaking, the shell doesn't flex when squeezing, and actuating the side buttons by pressing below them is impossible. And while the feet definitely aren't 100% PTFE as Corsair claims, as that would entail no black dye being used, they are very decent in terms of glide.

Of course, the M65 RGB Ultra also comes with an integrated weight system. Being a much lighter mouse than the M65 RGB Ultra Wireless to begin with, the M65 RGB Ultra gets more use out of a weight system, and the lower weight itself makes the M65 RGB Ultra more pleasing to use in general. The tilt-gesture system, on the other hand, still fails to provide any benefit. Thankfully, one isn't forced to use it, and the additional lift-off distance levels are quite useful in that they grant more granular control.

As expected from a Corsair mouse, the M65 RGB Ultra is compatible with Corsair's iCUE, which continues to have a nigh insatiable hunger for RAM and CPU time. I'd be more forgiving of that if iCUE would provide a function which I consider incredibly useful for mice capable of polling rates higher than 1000 Hz: game-specific profiles. With those, one can enable 8000 Hz or just 4000 Hz for those games that benefit from it while sticking with 1000 Hz for those who don't. With Razer Synapse, this is easily done, but with iCUE, polling rate needs to be changed manually over and over again. Again, this would be less of a concern if iCUE weren't as resource-hungry, but as it is, one has to live with this sort of resource usage if wanting to make use of the M65 RGB Ultra's full capabilities.

Overall, the conclusion for the M65 RGB Ultra is pretty simple. Those who know and like this shape from its countless predecessors find a competent mouse in the M65 RGB Ultra, provided one is lucky enough to get a unit with the "right" main buttons. At $69.99, the M65 RGB Ultra is fairly priced, too, considering the feature set and quality on display. Hence, the M65 RGB Ultra earns our Recommended award.

As far as competition goes, there are several other options. Corsair's own Sabre RGB Pro too comes with 8000 Hz polling, albeit not quite on the same level of execution, mechanical instead of optical switches, yet still very low click latency, and a similar cable, along with lower weight, for $59.99 instead of the $69.99 of the M65 RGB Ultra. The EVGA X17 too is capable of 8000 Hz polling, but trails both of Corsair's offerings when it comes to implementation, has lackluster click latency, a stiff cable, fairly high weight, and nonsensical side-button placement, but a software that is pleasantly low on resources, for $79.99. Lastly, the $159.99 ASUS ROG Chakram X Core has true 8000 Hz polling in wired mode, hot-swappable main button switches, outstandingly low click latency, great sensor performance, and a joystick, but is hampered by Armoury Crate, which is only good for providing nightmare fuel.