Build Quality

Overall build quality is mostly solid. When shaking the mouse, a rattle comes from the main buttons. When applying lateral pressure, major creaking but no 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 M900 Pro are good to very good. Pre-travel is moderate, and post-travel is low, resulting in a firm and snappy button response nonetheless. Despite being visually separated from the shell, button movement is fairly low even when provoked. Button stiffness is medium. A pair of Huano switches (blue transparent shell, pink plunger) are used.


Side buttons are good (back button) to very good (forward button). The forward button has low to moderate pre and moderate post-travel, whereas for the back button it is the other way around. In addition, the actuation point isn't entirely even on the back button. Nonetheless, button response is quite satisfying. Button size and placement are not ideal, as the side buttons sit too high to easily be able to actuate them by rolling one's thumb across. A set of Huano switches (white plunger) are used for these.

At the bottom of the mouse is a button for cycling through the set CPI levels, which works just fine. A seemingly unbranded tactile switch is used for this one. A slider at the bottom switches between on and off-state, which also works fine.

Scroll Wheel

The scroll wheel is decent. Noise levels are mostly under control, but tactility is below average, as the individual steps lack separation. The encoder comes from Huano (black, pink core) and has a height of 13 mm. The middle (scroll wheel) click requires high force for actuation. Another Huano switch (red plunger) is used for this one.

Surface

The M900 Pro has a matte surface all over. 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 M900 Pro is easy. The screws are found beneath the front and rear skates along with the dongle compartment door. After removing those, two additional clips at the sides need to be dislodged, which is easily done. When separating top and bottom shell, make sure not the rip the cable connecting the two.

The internal design is simple yet quite efficient. The side buttons sit on their own PCB screwed to the top shell and connected to the main PCB through a ribbon cable. The battery is placed towards the rear, partially covering the main PCB. Four screws are used to affix the very thin main PCB to the bottom shell, and all PCBs have holes for further weight-saving. The MCU is a Beken BK3633, whose datasheet can be found here.


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