My most-used 35 is the UC Hexanon 35/f2, which I really like for it's size and handling and also it's rendering wide open or nearly so, and when stopped down to f8 or narrower. I'm less convinced, though, at stops narrower than f8 and wider than about f2.8 - the rendering sometimes works for me and sometimes doesn't. I had planned to get a ZM 35/f2 Biogon as an alternative - but an M-Hexanon 35/f2 came my way and I couldn't pass it up. I find the M-Hexanon a good honest performer at all apertures. That leaves me a bit indecisive about which 35 to take along when I want to use one. Often (but far from all the time) it ends up being the UC Hexanon for the ergonomics, but mostly for the occasional "specialness" it can deliver.