I like several things about 645 Pro but it does have a needlessly cluttered interface. Please tell me why it shows ISO and a histogram when there is nothing I can do to affect them? Needless clutter as far as I'm concerned. I much prefer their other product, 6x6, for its simplicity. On the positive side, being able to select a range of aspect ratios is very cool. And their files are robust and very clean.
FYI: many camera apps now offer two finger adjustment for focus and exposure. Nothing earth shattering there.