Build Quality

Overall build quality is solid. There is a very minor 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 only for the back button and 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 Go XD5 are very good. The right button has some pre-travel and the left one some 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 good (back button) to very good (forward button). Pre and post-travel is low on both, but the back button doesn't feel entirely stable when pressed towards the back, and both buttons sound rather hollow, for lack of a better word. Button size and placement are good as actuation is possible rather easily by rolling one's thumb across. A set of Kailh switches (red plunger) is used for these.

At the top of the mouse is a single button for cycling through the set CPI levels, which works just fine. A seemingly unbranded tactile switch (blue plunger) is used for this one. At the bottom of the mouse, a slider switches between on and off-state, which too works perfectly fine. An additional button cycles through the available RGB lighting effects.

Scroll Wheel

The scroll wheel is very good. Noise levels are mostly under control, and 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. A seemingly unbranded tactile switch (black plunger) is used for this one.

Surface

The Helios Go XD5 has a smooth matte surface all over. Grip is fine, and it doesn't attract fingerprints, dirt, or the likes 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 Helios Go XD5 is fairly easy. The screws are located beneath the front skates and the sticker, roughly in the middle between the rear skates. After removing those, the top shell can be lifted with ease.

The internal design is equally simple. The side buttons and CPI button sit on their own PCB screwed into the shell and connected to the main PCB with a ribbon cable. Curiously, the side-button PCB also has a small LED that displays the currently active CPI step when cycling even though it is barely visible when assembled. The battery is glued directly to the main PCB, which is affixed to the bottom shell by four screws and, much like the side-button PCB, fairly thin. The MCU is a CompX CX52850.


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