Just to be contrarian, I like Ken Rockwell precisely because he is opinionated. I get more information from a critical review than from fan-boy enthusiasm.
Ken is a big film booster, and he was quite enthusiastic about the Pentax 645, 645N and 645NII. I'll be he gives high marks to the 645D when he gets to try it out.
He made a couple errors, notably about the fact that none of the "645" format cameras on the market are "FF 645". I agree with Ken about the superior user experience of the 645N, which uses manual knobs for each function and the "green dot = auto". I hate menu systems, stupid mobile phone keyboards and TV remotes.
Ken has a very useful article on the
Mamiya DM33 645 system, which addresses questions on this forum from a couple weeks ago, namely "what do you really get by going to a medium format sensor?" The big elephant in the room is Pentax's $9,400 price compared with $20,000+ for every other medium format digital at 40M.