Absolute silence
What could be more annoying than a mechanical (spring) noise every time you click your mouse?
At last, the problem has been solved for the mouse and the same for the keyboard. Everything is pleasant.
A lot of functions that will be useful to me (office use) but I quickly found the ones that interest me.
I had a little trouble redefining the mouse buttons, but you just have to look where you need to.
All in all: PERFECT.