I picked up a Leica CL and a Summicron C-40mm from our local camera store. I shot 2 rolls of film, Superia 400 and TX400. I am pretty amazed how small this lens is.
Scanned and developed by meinfilmlab on Fuji Frontier.
It does not render like the 35mm Summicron, maybe that is true on digital. But on 35mm film, it draws simular to my old Elmar 50mm/2.8. Sharp and natural colors.
I printed around 30 shots and came to the conclusion, that my 50mm Summicron (version 4) gives me more saturated colors and my old Elmar 2.8 suits better for black and white. I also found the handling not to my taste and the signature of the lens overall not significant enough.
But if you look for an entry into the Leica world, the Summicron 40mm is the best bargain lens. I highly recommend it.