I had the kitty pad and it didn't work well in Mac OS X so I sold it. I had to use auto hot key, and I don't like installing things like that.
And iirc the "kitty" pcb is non-reprogrammable.
I wouldof kept if it worked better in os x, it was really nice. I got it to go along with my gon ns 38gt.

I think GON is working on a new numberpad. (New PCB)
I saw it on otd.kr or kbdmania.net a while ago.
If he is working on a new pcb, the pros would be thats it's reprogrammable with smd leds spots on the bottom of the pcb to achieve richer glow in the middle clear/polycarb layer of the case.