I traded my Leica M8 for a like-new Zeiss ZM (Limited Edition) film body and Zeiss Sonnar 50mm f1.5 lens. The Sonnar is loved and hated, in equal strength, amongst photographers. I've written before about this lens, and how it's a modern implementation (latest lens coatings, materials, manufacturing) of a historic lens design. People who like to measure lens performance are not impressed. Many people who like to take pictures are impressed. Very impressed.
This is an example from the first roll of film I shot with this combination. I love the way it images. The color it provides is quite nice, but I think this is going to be a black and white lens for me. I can't wait to try some street photography with it.
I'm also looking forward to using the Sonnar on my M9.