Build Quality

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

Buttons

Main buttons on the Prime Mini are decent. Pre-travel on the left button is massive, to where there is low post-travel merely by virtue of pre-travel being so high. The right button has less pre-travel, but more post-travel to compensate. While the left button feels and sounds quite snappy, feedback on the right one is dull and muted, almost reminiscent of a tactile switch. Despite being visually separated from the shell, lateral button movement is as low as physically possible and cannot be provoked either. Button stiffness is medium. SteelSeries-branded Prestige OM switches are used.


Side buttons are good. Both pre and post-travel are virtually nonexistent, resulting in a very firm and snappy button response, further complemented by the pressure point being perfectly even across the entirety of these. However, compared to the Prime, these sound very hollow. Button placement is good as actuation is possible quite easily by rolling one's thumb across. A set of Kailh switches (grayish case, orange plunger) is used.

At the bottom of the mouse is a single button for cycling through the set CPI steps and polling rates. How this works isn't immediately obvious. In order to cycle CPI, one has to press the button once to enter CPI mode, and only then is it possible to cycle through the set CPI steps with further button presses. Similarly, pressing and holding the button cycles through the available polling rates from highest to lowest. A seemingly unbranded tactile switch is used for this one.

Scroll Wheel

The scroll wheel is good. Scrolling in either direction is really noisy, but tactility is on point, with clearly discernible steps and a matching tactile feel when scrolling. The encoder comes from TTC (black core) and has a height of 12 mm. The middle (scroll wheel) click requires medium force for actuation. A seemingly unbranded tactile switch is used here.

Surface

The Prime Mini has a slightly rougher matte surface all over. Grip is fine, but it does pick up fingerprints, dirt, and the likes quite easily. It is easy to clean, and there are barely any signs of wear left after doing so. All in all, good materials.

Button Sound Test

Disassembly

Disassembling the Prime Mini is easy. The biggest hurdle consists of the four Torx T6 screws located beneath the three skates. With those taken care of, top and bottom shell are easily separated. While the main button switches are part of the top shell and insert into two contact points on the PCB, the side buttons sit on their own PCB vertically mounted atop the main PCB. An auxiliary PCB next to the scroll wheel provides wheel illumination and is connected through a 5-pin connector. Three screws in total are used to affix the fairly thin and compact main PCB to the bottom shell. The MCU is a Holtek HT32F52341, whose datasheet can be found here.


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