In recent years, several mice have been released that challenged the notion of how much one can reasonably charge for a gaming mouse: The Logitech G Pro Wireless and Razer Viper Ultimate for $149.99 and the ASUS ROG Chakram for $159.99. Mad Catz prices the R.A.T. Pro X3 Supreme at $229.99, which is a whopping $80 ($70) more than the top-tier wireless mice just mentioned. For a wired mouse, that's no doubt a tall order. A $230 mouse had better be flawless, or at least reasonably close to perfection. Unfortunately, that is not the case.

From an engineering standpoint, the R.A.T. Pro X3 Supreme is no doubt impressive. The chassis is made out of several different materials, from plain plastic to magnesium alloy and metal. The ability to swap all four mouse feet with a second set of ceramic feet is realized very well, even including the ability to detach the entire sensor module. The main button switches sit elevated, and the entire side-button module on the left side can be detached and swapped to a different one. Coupled with the ability to adjust length and tilt of the back portion, as well as the countless different parts that can be changed for those installed by default, the R.A.T. Pro X3 Supreme indeed is modular to an unprecedented degree. Moreover, the R.A.T. Pro X3 Supreme offers plenty of customization within the software, including uncommon options such as angle tuning. All buttons can be rebound, and the RGB lighting can be adjusted to one's liking, too.

However, none of this actually matters if a mouse doesn't excel where it's supposed to—namely, in games. First of all, I had major trouble getting used to the shape of the R.A.T. Pro X3 Supreme despite all the provided customization options: It's either too short or too long for its width. Still, that may be a subjective thing and simply related to how I grip the mouse. The bigger issue is the placement of the "sniper button." It's located right below the side buttons; i.e., where the thumb usually sits. Accordingly, not actuating that button all the time becomes the biggest challenge when using this mouse. Given this button significantly lowers CPI when pressed, involuntarily pressing it is a huge liability. Of course, simply binding a different function or disabling the button altogether is an option, but still not a solution. That button is still there, and typically, one doesn't want to press it, which inevitably messes with one's mousing. It's beyond me why Mad Catz didn't provide at least a single side-button panel without this button. Not doing so on a mouse this big on customization is simply baffling.

Onto the sensor. PixArt's PMW3389 largely performs as expected—that is, as long as a polling rate of 1000 Hz is used. Much like on the R.A.T. 8+ ADV, the higher polling rates of 2000 and 3000 Hz are fake. In fact, 2000 Hz is equivalent to 3000 Hz, and what's worse, it messes with tracking. For some reason, actual CPI goes down when using either 2000 or 3000 Hz. Since Mad Catz decided to tune all CPI steps for those polling rates, actual CPI is much higher than intended when using 1000 Hz, resulting in massive CPI deviation. At least click latency is much lower than on the R.A.T. 8+ ADV. For the record, Mad Catz has reached out to me and is adamant that the 3000 Hz polling is real. For their perspective, please refer to the 3000 Hz section on the fifth page.

Another issue pertains to the scroll wheel. The middle (wheel) click on my unit has enormous pre-travel. In fact, it's massive to where it becomes difficult to actuate at all when gaming. Furthermore, the cable is as stiff as on the R.A.T. 8+ ADV, and for its size, the R.A.T. Pro X3 Supreme at 112 g weighs quite a bit more than other mice in its class. Lastly, although button quality is pretty good overall, the back side button in particular suffers from a poor actuation point and spongy response.

All of these issues would already be damning on a $50 mouse. On a $230 mouse, they're simply inexcusable. As nice as the mouse is in terms of customization, core performance simply isn't there.