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. Lastly, accidental clicks do occur when slamming down the mouse.

Buttons

Main buttons on the M2K are good. There is minor pre-travel, and the buttons bottom out past the actuation point by a decent amount. Click feel itself is somewhat dull and muted, yet strikes a good balance between firmness and being light enough to click, as a heavy click can be doubly irritating on a mouse this light. Two small screws below the switch pins can be used to adjust the click tensioning, though this should only be performed by advanced users. A pair of Omron D2F-01F (Japan) switches is used.

Scroll Wheel

The scroll wheel is excellent. Scrolling up and down is fairly quiet, and while scrolling is rather heavy, tactility is outstanding, providing clearly separated steps that are easy to control. The encoder comes from ALPS (EC10E1220501) and has a height of 9 mm. The middle (scroll wheel) click requires medium to low force for actuation. Another Omron D2F-01F (Japan) switch is used for this one.

Surface

The M2K has a matte surface all over. Grip is fine, and it doesn't attract fingerprints, dirt, or the likes too much. It is easy to clean, and there are no signs of wear left after doing so. All in all, excellent materials.

Button Sound Test

Disassembly

Disassembling the M2K can be difficult. Seven Torx (T6 and T4) screws are used, three of which fixate the PCB assembly to the carbon fiber shell, while the other four fixate the PCB to the assembly itself. The scroll wheel sits on its own PCB directly slotting into the main PCB. The main PCB is designed in the most efficient way possible, and all PCBs are very thin (1.0 mm) in order to save even more weight. Furthermore, compared to standard designs, the traces are thinner (0.1 instead of 0.3 mm), and instead of the usual electrolytic capacitors, multi-layer ceramic capacitors are used. The MCU is an STM32F730, whose datasheet can be found here.


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