Tim Gray
Well-known
Yes, the eyes... That's obviously a problem when choosing lenses for RF cameras. Even the threads saying "show your [insert whatever lens] pictures!" seldom contain more than a few pictures. 🙄
The 35/1.4 Nokton is probably one of the most rational choices. It seems sharp enough, is small and cheap. But, if I buy an M9 I'd really want something special. Perhaps the 1.4 Nokton is alright, but I'll have to seek for more picture samples first. My main concern with it (as it appears) is barrel distortion and quite harsh bokeh.
Well, there are comparison threads floating around that have reasonably extensive image documentation. Of course, I would just check out the M-mount group on flickr. Everything is organized there. Not head-to-head comparisons, but you can get a feel for how some of the lenses perform in different conditions.
The best thing about RF lenses - if you stick with lenses that are currently made, NONE of them are bad. Most of the ones not produced are damn good too, but there are some odd performers out there once you start digging back 40-50 years.