I have the bass and the keys and the beats are on order. I really like them both. They don't much of a feature overlap - they can both do tricks the other one can't. Korg have been pretty clever. I'm still having fun with mine. Since they have MIDI and accept CC data, they really are very open ended boxes. Fun on the go with the built in sequencer and battery power, handy in the studio hooked up to the OT. And c'mon....the price!
Here's my review of the keys:
Part 1
https://www.youtube.com/watch?v=uvYw0q1ir6IAnd part 2
https://www.youtube.com/watch?v=_F27D0jA9RE