Build Quality

Overall build quality is very solid. There is no rattle when shaking the mouse. When applying lateral pressure, minor creaking but no flexing of the shell can be observed. Activating the side buttons by squeezing the sides is impossible, although they do cave in when using excessive force. Lastly, no accidental clicks occur when slamming down the mouse.

Buttons

Main buttons on the Viper 8K are very good. Razer has steadily been improving their optical switches, and while I was far from thrilled about them on the DeathAdder V2 Pro, they're bordering on excellent on the Viper 8K. Compared to regular mechanical switches, the click feel is still somewhat dull, but both pre and post-travel are low, resulting in a snappy and highly satisfying click response. While the buttons are visually separated from the shell, lateral button movement is minimal. Button stiffness is light. Razer-branded optical switches are used here.


Side buttons are very good. The back button on the right side in particular has some noticeable pre-travel on my copy, but post-travel is fairly low, and click feel nice and snappy, along with an even actuation point. Button placement is good as actuation is possible quite easily by rolling one's thumb across. Two sets of CF switches (red plunger) are used for these.

On the bottom of the mouse is a single button for cycling through the set CPI levels. Its click feel is perfectly fine. A seemingly unbranded tactile switch is used for this one.

Scroll Wheel

The scroll wheel is very good. Scrolling up or down is somewhat noisy, but the individual steps are quite nicely separated, resulting in above average tactility. The encoder comes from Kaihua. Actuating the middle (scroll wheel) click requires medium force. A seemingly unbranded tactile switch is used for this one.

Coating

The Viper 8K has a slightly rougher matte surface. It 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, excellent materials.

Button Sound Test

Disassembly

Disassembling the Viper 8K is fairly easy. First, the top and bottom skates need to be removed, the latter of which is double-layered and therefore not as easy to get off. After the three screws have been unscrewed, top and bottom shell will still be held together by several clips, but unlike on the Viper Mini, it takes just a bit of additional force to dislodge them. Just make sure not to rip the cable connecting main and side-button PCB screwed into the top shell. The internal design is remarkably efficient. All PCBs are fairly thin, and there's virtually no unused space whatsoever on the main PCB. Three screws are used to affix the PCB to the bottom. The MCU is an NXP LPC5528, whose datasheet can be found here. The production date for the side-button PCB is the 42nd week of 2020.


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