Build Quality

Overall build quality is solid. When shaking the mouse, there is a rattle from the scroll wheel. When applying lateral pressure, no creaking of the shell can be observed. Lastly, when slamming the mouse down, no accidental clicks occur.

Buttons

Main buttons on the G604 are excellent. Pre-travel is very low and post-travel low, resulting in a snappy and satisfying click feel. While the clicks are separated from the main body, provoking any kind of button movement is virtually impossible. Button stiffness is light. Omron D2FC-F-7N (G) switches are used.


Side buttons are excellent. Both pre and post-travel are nonexistent, resulting in a snappy and tactile click response. The pressure point is even across the entire button, too. The six side buttons bulge outward, which makes it easy to tell them apart by feel. They are also easily actuated by rolling one's thumb over them. Furthermore, due to the side buttons being quite slim, there is still plenty of room for the thumb to rest below the side buttons or on the thumb rest, which is a great piece of design. Several tactile switches are used for these.

To the left of the left main button are two buttons for cycling through the set CPI levels (default). Their click feel is good. Two tactile switches are used for these. At the top of the mouse are a button for unlocking the scroll wheel and a button for switching between regular 2.4 GHz and Bluetooth mode. Their click feel is below average.

Scroll Wheel

The scroll wheel is very good. The metal construction provides a sensation of solidness that is otherwise absent on all-plastic wheels. Tactility is good as well, with clearly pronounced steps. The wheel isn't mounted too firmly, however, which results in unintended lateral movement. Additional utility is provided by the ability to use horizontal scrolling, as well as setting the wheel to spin freely. The middle (scroll wheel) click requires medium force for actuation. Another tactile switch is used here.

Coating

The middle piece and the sides appear to be made out of hardened rubber, which is soft to the touch and provides excellent grip. Both the front and back pieces, as well as the entire base, have a matte black coating similar to the coating on many other Logitech mice. It, too, provides very good grip and doesn't attract fingerprints, dirt, or the likes too much. Additionally, it's easy to clean, and there are no signs of wear left after doing so.

Button Sound Test

Disassembly

The most important thing to be aware of when disassembling the G604 is that the feet are double-layered. The second layer can easily be mistaken as part of the shell, so make sure to remove both layers. Beneath them you should find a total of five screws. Remove them and the bottom shell should come off. However, caution ought to be applied since a thin ribbon cable and a regular cable connect the top chassis and the bottom-shell PCB. After removing all the narrow-head screws, the chassis needs to be pushed out, with sufficient caution, of course. The bold-head screws all pertain to the buttons and need not be removed.


While the sensor sits on the bottom-shell PCB (internal illumination), all the buttons sit on their own PCBs encased in a chassis sitting within the top shell. The design is as unusual as it is sophisticated, as expected from Logitech.

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