I love my Ultron 35mm lens. It can look vintage soft at f/2 and f/1.7, but from f/2.8 and above it looks more modern sharp, without ever actually being modern sharp.
Also, the overall low contrast helps a lot when pushing film, for film gets too contrasty very quickly when pushed.
I however did not like my Skopar 35mm f/2.5. I tried to like it, but just could not. I loved the size, but could not get into the overly modern look (this is probably due to shooting BW film exclusively... if I shot color, I would still own it).