On the other posts, there were some questions. Not to divert the discussion there, I am posting here.
I read that contax g 45mm is similar to ZM 50 planar. It was the second sharpest lens tested on film by photodo. I prefer 45mm to 55mm for walking out and also the smaller size helps. Here is a comparison to other 35mm Sony/Zeiss lenses (g35mm and g45mm are same sizes):
Here are some g45mm shots with A7R using af adapter:
Lots of cat shots, but these should show the bokeh characteristics...