Build Quality

Overall build quality is 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 possible but requires excessive force. Lastly, accidental clicks when slamming down the mouse do not occur regardless of the set debounce time.

Buttons

Main buttons on the Helios XD3 V2 are very good. The left button in particular has some pre and moderate post-travel, but the button response is equally firm and snappy on either button. Despite being visually separated from the shell, lateral button movement is minimal. Button stiffness is medium. A pair of Kailh GM 8.0 (80 M) switches is used.


Side buttons are decent. There is some pre-travel, and the back button in particular can be pushed in way past the actuation point. The pressure point on the back button in particular isn't entirely even, either. Button size and placement are good as actuation is possible rather easily by rolling one's thumb across. A set of tactile switches from presumably MWK is used here.

At the top of the mouse is a single button for cycling through the set CPI levels, which works fine, even though it sitting almost flush between the main buttons can make it difficult to actuate the button without actuating the main buttons. A Huano switch (white plunger) is used for this one. At the bottom of the mouse is a slider which switches between off-state, on-state with illumination enabled, and on-state with illumination disabled ("eco"). Functionally, the slider is perfectly fine.

Scroll Wheel

The scroll wheel is good to very good. Scrolling upwards in particular is noisy, but tactility is quite good, providing nicely separated steps and controlled scrolling. The encoder comes from F-Switch (black, black core) and has a height of 11 mm. The middle (scroll wheel) click requires medium to high force for actuation. Another switch from Huano (green plunger) is used.

Surface

The Helios XD3 V2 has a smooth matte surface all over. Grip is fine, but it does attract fingerprints, dirt, or the likes somewhat readily. It is easy to clean, and there are no signs of wear left after doing so. All in all, good materials.

Button Sound Test

Disassembly

Disassembling the Helios XD3 V2 is very easy. The screws are located beneath the front and rear skate. After removing those, the top shell can be lifted with ease.

The internal design is equally simple. Everything aside from a small auxiliary PCB which provides wheel illumination sits on the main PCB. The battery is affixed to the top shell with a sticky pad, while the side buttons are mounted vertically atop the main PCB. Two screws in total are used to secure the main PCB, which is both thick and large. Going with a thinner and more compact PCB would have been a viable way to save a lot of weight. The MCU is a CompX CX52850. Production date for the main PCB is the 44th week of 2021.


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