Build Quality

Overall build quality is very solid. When shaking the mouse, a very minor rattle comes from the side buttons. When applying lateral pressure, no creaking or 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.

Please note that the disassembly pictures have been taken from the Prime review as the internal design of the Prime makes showing the individual parts more convenient. The parts themselves are identical.

Buttons

Main buttons on the Prime+ are very good. Pre and post-travel is low on the left button, whereas the right one has low pre-travel and moderate post-travel. Compared to my sample of the regular Prime, button response is still muted, but not lacking in feedback as much, and instead quite a bit snappier and defined. 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 excellent. 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. Button placement is good as actuation is possible quite easily by rolling one's thumb across. A set of Kailh switches (grayish case, red plunger) is used.

At the bottom of the mouse is a single button next to the OLED screen. For more details on how this works please refer to the OLED section on the second to last page. A seemingly unbranded tactile switch is used for the OLED button.

Scroll Wheel

The scroll wheel is good to very 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 12.6 mm. The middle (scroll wheel) click requires medium force for actuation. A seemingly unbranded tactile switch is used here.

Coating

The Prime+ 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+ isn't too difficult. 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 easy to separate. Curiously, the internal design differs quite a bit from the Prime. Similarly to the ROCCAT Kain series, most of the internals are screwed to the top shell, including the scroll wheel and side buttons. Both the scroll wheel and auxiliary wheel illumination PCBs are connected to the side-button PCB, which in turn is connected to the main PCB through a ribbon cable, while the main buttons have their contact points directly on the main PCB. In practice, doing it like this doesn't make much of a difference, which is why I find the decision to go with this design over that of the Prime somewhat puzzling, especially when considering that the only area where the Prime+ is different from the Prime is the bottom of the main PCB. Two screws in total are used to affix the fairly thin and compact main PCB to the bottom shell. The MCU is located on the bottom of the main PCB. An STM32F103CBT6 is used, whose datasheet can be found here.


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