All, I purchased a ZF 50mm, tested it against my Nikkor AF 50mm f1.4, on a stable tripod, in the shade at 10-16 ft, with Delta 100ASA . The ZF is better. So much so I sold the Nikkor. I have since purchased (second hand cos' they are expensive) a ZF 35mm f2. Love it. Its the only fixed focus 35mm I have owned but its great. grips with the 50mm none. Grips with the 35mm -yes, why it it so dame big and heavy, yes lots of glass but the manual Nikkor 35mm f1.4 is lighter? If you can find one second hand, and don't mind the weight, get one.
Over all I am happy with my ZF's, something Im can't say about all my Nikkor (I owned/hane owned 7 of them).
Old cosina cameras -yes I have a CSM and my father a CSL and a CS3. OK, had a small problem with the CSL which could be overcome (depth of field preview button would stick in if pressed to hard. I would put them on par with chinon, but below the old BIG 5 makes.
Regards