The 35/2R is very sharp in the middle, but has dramatic field curvature. At the time that I owned one, I never really figured out how to use it and hated it. Now I think I am much more accepting of that kind of thing, looking for the strengths in each lens. The Zeiss 35/2 has very strong, almost exaggerated 3D and higher contrast, a more punchy lens, whereas the 35/2R is more subtle. I would say that the Zeiss 35/2 is maybe better for typical walk-about kind of photography, with the Leica being better for people, but this is clearly a matter of taste. The Contax and ZF/ZE 35/1.4 is a different beast, a lens of a higher class, more expensive, larger, with better rendering, IMO. The 35/1.4 lenses would compare more with the 35/1.4R.