Build Quality

Overall build quality is solid. There is no rattle when shaking the mouse. When applying lateral pressure, minor creaking and 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.

Buttons

Main buttons on the M3 Gen II are good. Pre-travel is moderate, but post-travel is low, and button response quite snappy and firm, though a bit duller on the right button. Button stiffness is medium. A pair of TTC Gold (60 M) switches are used.


Side buttons are good to decent. There is some pre-travel, and post-travel is moderate, leading to a rather snappy button response, though feedback on the forward button is rather dull and subjectively less than pleasing. The pressure point is even across the entirety of these. Button placement and size is good as actuation is possible very easily by rolling one's thumb across. A set of Kailh switches (white plunger) are used for these.

At the top of the mouse is a single button for cycling through the set CPI levels. Another Kailh switch (white plunger) is used for this one.

Scroll Wheel

The scroll wheel is good. Scrolling up is noisy, whereas scrolling down is mostly quiet, and tactility is merely average, with rather well-separated steps affording a decent degree of control. The encoder comes from Kailh (gray) and has a height of 12 mm. Actuating the middle (scroll wheel) click requires high force. A Huano switch (green plunger) is used for this one.

Surface

The M3 Gen II has a rougher matte surface on the sides and a smoother surface on the top. Grip is fine, and it doesn't attract fingerprints or dirt 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 M3 Gen II is difficult. Unlike on most other designs, the screws are found under the sticker instead of beneath the skates. After removing those, three hooks at the sides and rear of the shell need to be dislodged as well, which may require destructive force.

The internal design is simple yet effective. All components are located on a single PCB, and the side and top buttons are actuated by stems that are part of the top shell, which works reasonably well. The PAW3318 is a SoC (full designation: PAW3318DH-TKSL, H2404435CE) and thus requires extra space, which is why the main button and scroll wheel switches have been rotated by 90 degrees.


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