Never played the G70 but the BK9 has a very decent keybed. Full size 76 keys. I prefer a real piano keyboard but for doing organ type things the BK9 is just right. I'm very happy with mine.
That price isn't bad so do some bargaining and good luck
_________________________
Bill in SC --- Roland BK9 (2) Roland BK7M, Roland PK5 Pedals, Roland FP90, Roland CM30 (2), JBL Eon Ones (2) JBL 610 Monitor, Behringer Sub, EV mics, Apple iPad (2) Behringer DJ mixer