Build Quality

Overall build quality is solid. There is no rattle when shaking the mouse. When applying lateral pressure, some creaking but no 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 Pro X Superlight 2 are decent (left click) to very good (right click). On my sample, button response differs greatly between the left and right main buttons. Both buttons have some pre-travel along with low post-travel, but whereas the right button feels sharp and defined, the left one is muted, hollow, and emits a rather irritating "ping" noise upon actuation. In addition, the left button is significantly louder and more irritating than the right one. While the buttons are visually separated from the shell, lateral button movement is quite low even when provoked. Button stiffness is medium. A pair of Omron D2FP-FH1 (China) switches are used.


Side buttons are subpar (back button) to good (forward button). While the forward button has fairly low pre and post-travel, albeit slightly mushy actuation nonetheless, the back button suffers from noticeable pre-travel, uneven actuation, and an even mushier response. Button size and placement are good, as actuation is possible rather easily by rolling one's thumb across. A set of surface-mounted Omron D2LS-21 switches is used for these.

At the bottom of the mouse is a simple on/off-slider, which works fine.

Scroll Wheel

The scroll wheel is decent. Noise levels are elevated, and tactility is merely average, as the individual steps aren't particularly distinct, yet allowing for decently controlled scrolling nonetheless. The encoder comes from TTC (white or "Silver") and has a height of 8 mm. The middle (scroll wheel) click requires medium to high force for actuation. A seemingly unbranded tactile switch is used for this one.

Surface

The Pro X Superlight 2 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 Pro X Superlight 2 is reasonably difficult. After removing the top and bottom skates, no less than six screws need to unscrewed, after which the top and bottom shell are easily separated.

The internal design is essentially unchanged compared to the Pro X Superlight. An endoskeleton is used, which can only be separated from the top shell once the main button pieces have been removed first. The main PCB holds the sensor as well as the USB connector and not much else, and is connected to the main-button PCB through an FFC (flat flexible cable). The latter PCB holds the main buttons, scroll wheel encoder, and scroll wheel switch, and is affixed with four screws to the endoskeleton. Another three screws affix the main PCB to the bottom. The MCU is rear-mounted on the main PCB and is a Nordic nRF52840, whose datasheet is found here. The Bluetooth capability of the chip remains unused. Production date of the main PCB is the 22nd week of 2023.


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