I have a friend I've known for 49 yrs (We were photographers in the Army together). He was a commercial photographer in Manhatten for a long time (a real New York Pro). He heard about this husband/wife couple who used Leica slrs in their professional work. They had the lenses modified by a repairman (who, I don't know)---he reshaped the aperture blades & did something else (what, I don't know)--the result was significantly sharper pictures! So I guess any Leica slr lens you can buy just doesn't live up to it's full potential.