Excellent typing comfort (fast and accurate), but with noise (hard to have one without the other). Good quality of materials other than the plastic of the wrist rests light and brittle. Another negative point, the glossy coating around quite messy keys. The backlight is powerful with two levels of intensity and the ability to adjust the WASD keys differently and those of the directional arrows. The knob to the sound setting is very convenient. The G keys to record macros (can also record directly touches of profiles for many games recognized by the programming software downloaded on the Logitech website.
For non players I recommend the Logitech Illuminated Keyboard, less bulky, with discreet shapes and colors, with a backlight significantly less powerful and really hits silent (but less comfortable because the keys are very close).