Build Quality

Overall build quality is very solid. When shaking the mouse, a minor rattle comes from the sniper button. 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, accidental clicks when slamming down the mouse do occur if "Button Response Optimization" is disabled within iCUE; if enabled (default), they do not.

Buttons

Main button quality on the M65 RGB Ultra Wireless depends on which batch the unit is from. The initial launch batch comes equipped with a pair of Omron D2FP-FN (China) switches, which are poor. For lack of a better word, the left button on my unit can only be described as defective. Button response is mushy, spongy, and a mix between squeaking and creaking is emitted upon actuation. While the right button doesn't feel defective, button response is far from stellar, displaying moderate pre and post-travel along with a rather muted click feel. Later batches, on the other hand, come with optical switches from TTC, which are good. Button response isn't as sharp and defined, but the switches are much more uniform. On the left button, pre and post-travel are low, whereas pre-travel is moderate and post-travel low on the right button. The buttons are visually separated from the shell, and lateral button movement can be provoked very easily, although I didn't notice much of it during use. Button stiffness is medium.


Side button quality yet again depends on the batch. On the initial launch batch, the side buttons are poor, as both the forward and back button suffer from high pre-travel, with the back button being the greater offender, to where the button can be pressed in several millimeters before actuation. Post-travel is enormous as well, especially on the forward button, which can be pushed in to a large degree. Actuation is even across the forward button, but not at all across the back button. The click feel itself is somewhat pleasing, but greatly undermined by the subpar button design. Looking at the design, the side buttons being this poor is no wonder: The side-button PCB is slotted vertically into the base, so only the PCB itself provides some resistance, but due to being neither thick enough nor sufficiently fixated, the whole thing bends when pressing the buttons. The PCB is poorly fitted as well, as made evident by the gap between the back button and switch. On later batches, this has been improved, and the gap is much smaller now. Still, pre and post-travel on the back button continue to be significant. Button placement is good as actuation is possible quite easily by rolling one's thumb across. A set of Kailh switches (cyan plunger) is used here.

The sniper button fares much better, as both pre and post-travel are low, and the actuation is quite pleasing. The button is mostly out of the way yet perfectly within reach, and there is sufficient room for the thumb. Another Kailh switch (cyan plunger) is used for this one.

At the top of the mouse are two buttons for cycling up and down through the set CPI levels. Their click feel is very good. A set of surface-mounted Kailh switches (yellow plunger) is used for these. At the bottom of the mouse is a slider alternating between 2.4 GHz, Bluetooth, and off-state, which works just fine.

Scroll Wheel

The scroll wheel is good. It is fairly noisy when scrolling in either direction, and in particular when scrolling up a loud grinding noise can be heard occasionally. On the other hand, the individual steps are fairly well-separated, resulting in above average tactility. The encoder comes from Kailh (black core) and has a height of 6 mm. Actuating the middle (scroll wheel) click requires medium to high force. A seemingly unbranded tactile switch is used for this one.

Surface

The M65 RGB Ultra Wireless has a smooth matte surface on the top and textured plastic on the sides. The coating is pleasingly soft to the touch, but does attract fingerprints, dirt, or the likes quite a bit. It is easy to clean, and there are hardly any signs of wear left after doing so. All in all, good materials.

Button Sound Test

Disassembly

Disassembling the M65 RGB Ultra Wireless is fairly easy. No more than the two screws readily exposed on the bottom need to be unscrewed. From there, the top shell can be popped off after sufficient nudging. Some caution ought to be taken as a ribbon cable goes to the top-button PCB.

The internal design is quite complex. The main PCB holds the main button switches, scroll wheel, and MCU, whereas the sensor sits on its own PCB below. The battery sits on a sticky pad placed atop the main PCB. The CPI buttons have their own PCB screwed into the top shell and connected through a ribbon cable. The same goes for the side buttons, which are vertically slotted and connected through a 4-pin connector. Finally, there is a separate PCB for the USB connector, which slots into the main PCB. Three screws are used to affix the main PCB, another three to affix the sensor PCB, and all PCBs are rather thick. The MCU is a Nordic nRF52840, whose datasheet can be found here.


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