Maybe I got a bad copy, or I had higher expectations coming from medium format primes, but I just don't think it's all that special. It's a nice range, but I've got a Tamron 17-50 f/2.8 for crop bodies that's easily it's equal or better from an image standpoint. Now you do have to factor in the "L features" like internal focusing and very smooth/quiet operation and maybe that makes up the price difference. Not bad at f/8 and 11 and falls off quickly on either side.
I still feel it's overhyped by people who are comparing it to kit lenses.