I was thinking about selling my Mamiya m645 1000s with 45, 55, 80, 150, & 210 along with my crown graphic with ektar 127 & rodenstock geronar 210. In their place I'm thinking about buying a Pentax 67 setup. I know I will not miss the m645. I'm not sure about the 4x5. Even though I've only shot maybe 8 sheets during the last year. Any opinions on the Pentax 67?