There are several posters on this thread who use a 645D and I'm curious who among them or new users of Pentax plan on getting a 645Z. I'm torn between getting an A7r (and lenses) vs. a 645Z. The high ISO capabilities of the Z will solve vibration problems I have with slow shutter speeds on the D using long focal lengths. On the other hand, I could invest in the Sony and have a camera I could use everywhere without lugging the mass of the 645.
I could get both, but aside from the fact that my wife would kill me, I'm better off using one system. Thoughts?