I rented this lens and the Canon EF 24mm f/1.4 L II to see if the Zeiss was worth the extra cash and whether I could deal with the manual focus on my 5D Mk III. I know there are manufacturing variations from one sample to another, so it's hard to say whether my experience will be the same as your's.

When I first received the Zeiss Milvus 21mm f/2.8 Lens, my first declaration was that this is the world's most beautiful lens . More good news is that this lens feels at least as good in your hands as it visually appears and it mechanically functions with similar quality.