The 85/1.4 C/Y is 'dreamy' on film wide open - unfortunately this looks a bit 'fuzzy' on digital. Sharpens up by f2, really crisp at f4
90/2 Summicron
(old tests on a 5d)
The 90/2 APO is really sharp. Corners adequate at f2, sharp a stop in. Great color/contrast. Front bokeh can be a little harsh, but rear bokeh is fine. One thing I like about it is no longitudinal chromatic aberration, which is really obvious on the 85L/1.2. Nice compact lens, compared to the 85L and 85c/y.
Summicron:
Zeiss: Softer OOF transitions
In terms of handling, the EOS/Leica adapters seem much more secure, solid and stable than EOS/CY adapters (might have improved over the last few years, but I've got lots of 'wobbly' adapters, and the 85c/y is fairly heavy, and my adapters seem a little 'sloppy' compared to R).