I am completely satisfied with this keypad: pleasant to the touch, beautiful workmanship, good grip on surfaces, beautiful aesthetics, flawless ergonomics ... in short happiness. And it comes from someone very critical and not easily satisfied ... ;-)
The USB receiver 'unifying', that installs in seconds, works perfectly duplicate use keypad + mouse (I took a M505). It is very developed.
In short, a flawless Logitech regarding this keypad.