I just got the RB67 pro-s and so far I love it. I got mine with a lens and the 120 back from KeH for around $300 (Bargain rating but it looks in great shape) There is a bit of a learning curve but the image quality is incredible. Depending on what you're looking for an RZ maybe a better fit. There's a video on youtube comparing the models (this person decided on the RZ.) The RB is entirely mechanical, the RZ is more modern (metering, hot shoe, etc) but as such requires a battery to operate.