I have just completed my latest B&W portfolio, which was shot entirely on the 645Z, using 28-45 SR, 75mm FA and 80-160 A lenses.
You can
read about the trip here, see a more images and then the rest of the portfolio.
During my last trip, I shot almost 50% of the images on the Ricoh GR (well, its a Pentax really) and the rest on the Sony A7 and A7R. The 645Z of course also has a family sensor and its great to work with files that have so much in common. The 645Z blew me away with its performance and I will write about that in due course. What a camera...
If you have any questions, please ask!