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. It's impossible to activate the side buttons by squeezing the sides. Lastly, no accidental clicks occur when slamming the mouse down as long as a debounce time setting of more than 0 ms is chosen.

Buttons

Main buttons on the Model O Wireless are excellent. Both pre and post-travel are very low, resulting in a firm and satisfying click response. Though the main buttons are separated from the mouse body, button wiggle is minimal. After some use, I can feel the buttons moving slightly below my fingers, but it's barely noticeable in use. Button stiffness is light. Omron D2FC-F-7N (20M) (OF) (China) switches are used.


Side buttons are excellent. Both pre and post-travel are low, resulting in a snappy click response. The pressure point is even across the entirety of these. They're quite small and thin, but actuation by rolling one's thumb across is still perfectly possible. A set of Huano switches (green plunger) is used for these.

At the top of the mouse is a single button for cycling through the set CPI levels. Its click feel is good. Another Huano switch (green plunger) is used for this one.

Scroll Wheel

The scroll wheel is very good. Scrolling in either direction produces barely any noise, and the individual steps are quite nicely separated, resulting in good tactility. The encoder comes from F-Switch. The middle (scroll wheel) click requires medium force for actuation. Another Huano switch (green plunger) is used here.

Coating

The matte coating of the Model O Wireless is very similar to the matte coatings of the Model O, O-, D, and D-. It's very grippy and doesn't attract fingerprints, dirt or the likes too much. It's easy to clean, and there are no signs of wear left after doing so. All in all, an excellent coating.

Button Sound Test

Disassembly

Disassembling the Model O Wireless is quite easy. First, remove the two rear skates and the screws beneath. Once those are taken care of, simply pop the top and bottom shells apart. Some caution ought to be applied as several ribbon cables connect top and bottom.

The internal design is pretty much as efficient as it gets. The battery is located on the side-button PCB, which is screwed to the top shell. A 3-pin JST connector connects the battery to the main PCB, while a ribbon cable connects everything else. Two additional ribbon cables coming from the main PCB power the side LED strips. An auxiliary PCB next to the scroll wheel provides wheel illumination. The main PCB itself is absolutely packed. While the side-button PCB is very thin, the main PCB is of medium thickness. No more than a single screw and two pins are used to affix the main PCB to the bottom shell. The MCU is a Nordic nRF52840, whose datasheet can be found here. I can also spot an additional IC with the marking "V3533 3731."


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