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, and it's impossible to activate the side buttons by squeezing the sides. Lastly, no accidental clicks occur when slamming down the mouse.
Main buttons on the Keris are excellent. Pre-travel is low and post-travel moderate to low, resulting in a very firm and satisfying click response. Click feel is snappy, but a bit dull and muted. Button stiffness is light. ROG Micro Switches are installed by default, but can be replaced with either Omron D2F Series (D2F, D2F-F, D2F-01, D2F-01F) or Omron D2FC Series (D2FC-F-7N, D2FC-F-7N (10M), D2FC-F-7N (20M), D2FC-3M) switches. Changing the switch is as simple as pulling the old one out and putting the new one in.
Side buttons are very good. While pre-travel is low, they can be pushed in a bit past the actuation point, even though that has to be done intentionally and isn't noticeable otherwise. The actuation point is even across the button, and size and placement are great as actuation is possible rather easily by running one's thumb across. A set of Kailh switches (blue plunger) is used.
At the bottom of the mouse is a single button for cycling through the set CPI levels, which works just fine.
The scroll wheel is very good. Scrolling in either direction is quite noisy, but tactility is great, resulting in tight and controlled scrolling. The encoder is from Kailh. The middle (scroll wheel) click requires medium to high force for actuation. A seemingly unbranded tactile switch is used for this one.
Coating
The Keris features a whole host of surface materials. The main button pieces are made out of PBT polymer and feature a coarse yet oddly soft surface. The front portion of the sides is made out of ABS plastic, but rougher than the rest of the shell, which is almost entirely smooth. In either case, grip is fine, and the surface doesn't attract fingerprints, dirt, or the likes too much. It's easy to clean, and there are no signs of wear left after doing so. All in all, excellent materials.
Disassembly
Disassembling the Keris is very easy. All screws are exposed, so just remove their covers and unscrew them. The top shell can then be pulled off fairly easily. When putting the mouse back together, make sure to clip the front in first. The internal design is equally simple. Everything but the main buttons sits on a single PCB, even the side buttons. The side-button pieces have stems that push on the switches, which works surprisingly well. The main buttons reside on their own PCB placed right below the main PCB. I'm unsure as to why this design is used. An auxiliary PCB next to the scroll wheel provides wheel illumination. Several screws are used to keep the PCBs in place, and the PCBs themselves are fairly thin. The MCU is an STM32F072CBU6, whose datasheet can be found
here.
As for the soldering and general quality of the PCB, I'm unable to find any noteworthy flaws.