Ok, I've got an opportunity to buy an RB67 later. However, I enjoy using the 6x6 square format. I'm still unsure whether it's possible to shoot 6x6 on the Mamiya RB. ideally it'd be nice to have one camera that can shoot 645, 66 and 67. Also, how do Mamiyas lenses compare to Bronica's. I've been using a C330S TLR and so far I've been unimpressed. It's a tricky decision.