Build Quality

Overall build quality is very solid. There is no 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 impossible. Lastly, accidental clicks when slamming down the mouse do occur if "Button Response Optimization" is disabled (default) within iCUE; if enabled, they do not.

Buttons

Main button quality on the M65 RGB Ultra 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 decent. These have moderate pre-travel and low post-travel, resulting in a firm yet slightly mushy button response. In terms of feedback, the clicks feel very sharp, but not necessarily snappy. 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. Pre-travel is moderate on both buttons, whereas post-travel is low. 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 buttons are decent. The back button suffers from enormous post-travel as well as uneven actuation across the button, but post-travel is nowhere near as bad on the forward button, and pre-travel on both too is mostly under control. Button placement is good as actuation is possible quite easily by rolling one's thumb across. A set of Omron D2FC-F-7N (10M) (China) switches is used here.

The sniper button has low pre and post-travel, and the actuation is quite pleasing. The button is out of the way yet perfectly within reach, and there is sufficient room for the thumb. Another Omron D2FC-F-7N (10M) (China) switch 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 (green plunger, blue shell) is used for these.

Scroll Wheel

The scroll wheel is good. It is fairly noisy when scrolling up in particular, but the individual step are separated nicely, allowing for controlled scrolling. The encoder comes from Kailh (pink core) and has a height of 6 mm. Actuating the middle (scroll wheel) click requires medium force. A seemingly unbranded tactile switch is used for this one.

Surface

The M65 RGB Ultra 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 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 applied 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, connected through a 4-pin connector. 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. Three screws are used to affix the main PCB, another three screws to affix the sensor PCB, and all PCBs are rather thick. Production date for the top-button PCB is the 15th week of 2021, while production date for the side-button PCB is the 34th week of 2020. The MCU is an NXP LPC54605J512, whose datasheet can be found here.


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