I do not own the camera system or any of its lenses, but the photography department of my school has a Mamiya 7ii and the 43mm, 50mm, 80mm and 150mm lenses, which I borrow on their weekly check-out system whenever I possibly can.
I haven't yet used the 50mm, but I can attest to the several pros that the 43mm has.
- very, very sharp
- at f/16, hyperfocal distance almost covers the lens' entire focusing scale, at f/22 hyperfocal distance covers beyond the entire focusing scale.
- increased hand-held ability due to short focal length, goes without saying
- easy to focus
- brightlines in the external finder are easily visible, built-in diopter as well
cons -
- awkward to use with external finder, but this is possibly just my general clumsiness when it comes to alternating between rangefinder and viewfinder
- more expensive
edit - give me a little more time, say an hour or so, and I should be putting up one of my scans from a print with this lens