Got mine at home like 30min ago, and I'm already playing with it.
People complains about the polling rate. Do I actually feel any kind of lag? No, I don't. It feels exactly as my mech kb, except that my kb has blue switches, which are noisy as fuck. It is pretty comfortable since it is 10 times smaller than a kb, so I can place my hand much better.
I could chose between different switches, and decided to go for the Cherry MX red. It comes with 2 o-rings included on every key, which make the keys pretty silent.
U don't need to configure anything, u just plug in the keypad into the usb and it works properly. The default binded keys seem to be Z and X, and ESC on the red button on the left side.
I'll be playing with it from now on, need to get used to it.