The Logitech Wireless Illuminated Keyboard leaves a highly positive impression overall but, as is often the case, there is a tiny fly in the ointment. It is the short left Shift here. By default, I use Alt+Left Shift to switch my keyboard layout and I often miss the left Shift, hitting the neighboring backward slash instead. Most annoyingly, I do not use that slash at all! If I need it, I press the backward slash button next to the Enter one. This refers to the Cyrillic version, though. The American version of the keyboard has a long left Shift, which is far more convenient.
Other than that, I can’t really find any serious fault with the Wireless Illuminated Keyboard K800. The return of the classic editing block is welcome. The mechanics and ergonomics are all high quality. The keys move softly but have a distinct click. The tactile impressions are most agreeable. Of course, the keyboard is not silent because the scissor-switch mechanism is clicky by its very design. However, the noise level is rather low and you won’t disturb your family’s sleep with this keyboard even if you work at nights.
I didn’t find the Incurve Keys to be particularly handy. Perhaps another style of typing is necessary to appreciate it fully. But the plastic of the keys feels nice to the touch and isn't slippery. The same goes for the wrist wrest. It is a one-piece thing, which is its only downside. By the way, it is in that wrist wrest that the sensor is located for turning the keyboard on as you move your hands towards it.
The backlight is excellent although not a breakthrough after the wired Illuminated Keyboard. The 4-level brightness adjustment allows to set it up for working comfortably at night. In daytime, the key markings look just light gray. I could not make the ambient light sensor work, but it wasn’t a problem for me. The keyboard might as well be without it altogether because its backlight regulation options are so flexible.
The exclusive software works well, too. The only thing that calls for improvement is the reporting of the battery charge level. I didn’t have enough time to check out the battery life, but I had the keyboard working much for four days at the maximum brightness of the backlight after being fully charged and its charge level dropped to one indicator segment as the consequence.
Another small advantage is the compact size of the device whereas the easily soiled glossy edging of the keys is a downside.