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.

Buttons

Main buttons on the Hati-S2 8K are good. Pre-travel is moderate to high, whereas post-travel is low, resulting in a fairly firm and snappy button response nonetheless. Being visually separated from the shell, button movement is moderate when provoked. Button stiffness is medium. A pair of Huano switches (blue transparent shell, pink plunger) are used.


Side buttons are excellent (forward button) to good (back button). Whereas the forward button has very low pre and post-travel, pre-travel is moderate on the back button, which has it feel mushier and less satisfying to press. The actuation point is even across the entirety of these. Button size and placement are good, as actuation is possible rather easily by rolling one's thumb across. A set of 2-pin, low-profile Omron switches (blue plunger) are used for these.

A slider at the bottom switches between on and off-state, which works fine.

Scroll Wheel

The scroll wheel is very good. Noise levels are mostly under control, and tactility is great, with clearly defined steps allowing for controlled scrolling. The encoder comes from TTC (blue, yellow core) and has a height of 9 mm. The middle (scroll wheel) click requires high force for actuation. A seemingly unbranded tactile switch (black plunger) is used for this one.

Surface

The Hati-S2 8K 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 Hati-S2 8K is trivial. The screws are readily exposed, and after dislodging the eight clips arranged around the base, top and bottom shell are easily separated. When doing so, make sure not to rip the cable connecting the two.

The internal design is highly 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 sits on a sticky pad residing on the main PCB, though due to its small size, the battery has a tendency to get unstuck. The very thin main PCB is affixed to the bottom with six screws, and has been extended such that it supports the structural rigidity of the shell. The MCU is a Nordic nRF52840, whose datasheet can be found here. The Bluetooth capability of the chip remains unused.


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