In my Guide to Leica I revisit three 35mm lenses for Leica M:
- Leica 35mm f/1.4 Summilux-M ASPH FLE (2010 version).
- Leica 35mm f/2 Summicron-M ASPH.
- Zeiss 35mm f/2 Biogon.
The 35mm focal length being the most natural on the Leica M, the choice of a 35mm lens is thus one that should be of keen interest to most M users.
I might post one or two more comparisons, but I’ve satisfied myself (with this one and others) that this one fairly represents the relative lens performances.