Build Quality

Overall build quality is very solid. There is no rattle when shaking the mouse. When applying lateral pressure, no creaking or flexing of the shell can be observed. Activating the side buttons by squeezing the sides is impossible. Lastly, accidental clicks when slamming down the mouse do not occur, provided the slam-click filter is enabled.

Buttons

Main buttons on the XM2w 4K are very good. Pre-travel is moderate, whereas post-travel is low, resulting in a firm and snappy button response. Despite being visually separated from the shell, button movement is low even when provoked. Button stiffness is medium. A pair of Kailh GX (80 M) switches are used.


Side buttons are excellent (forward button) to very good (back button). Pre and post-travel are minimal on either button, but feedback is more hollow on the back button. The actuation point is even across the entirety of these. Button size and placement are good, as actuation is possible easily by rolling one's thumb across. A set of Kailh GM 2.0 switches (black plunger) are used for these.

At the bottom of the mouse is a single button for cycling through the set CPI levels, which works fine. A seemingly unbranded tactile switch is used here. In addition, a simple on/off-slider is found here as well, which too works fine.

Scroll Wheel

The scroll wheel is good to very good. Noise levels are elevated, but tactility is very good, with clearly defined steps allowing for controlled scrolling. The encoder comes from TTC (white or "silver") and has a height of 5 mm. The middle (scroll wheel) click requires medium to high force for actuation. Another Kailh GM 2.0 switch (black plunger) is used for this one.

Surface

The XM2w 4K has a matte surface all over. Grip is fine, but it does attract fingerprints and dirt to an above average degree. That said, it is fairly easy to clean, and there are barely any signs of wear left after doing so. All in all, good materials.

Button Sound Test

Disassembly

Disassembling the XM2w 4K is very easy. The screws are found beneath the front and rear skates. After removing those, two additional clips at the sides need to be dislodged. When separating the top and bottom shell, make sure not to rip the cables going to the top shell.

The internal design is highly efficient. The side buttons sit on their own PCB screwed into the top shell and connected through a 4-pin connector to the main PCB, whereas the scroll wheel along with its encoder is hooked to the top shell and connected through a 3-pin connector. All PCBs are very thin, and the very compact main PCB has been affixed to the bottom with four screws, three of which are also used for a plastic assembly erected above the sensor holding the battery. The MCU is a Nordic nRF52840, whose datasheet can be found here. The Bluetooth capability of the chip remains unused. Production date for the main PCB is the 20th week of 2024.


As for the soldering and general quality of the PCB, I'm unable to find any noteworthy flaws.