I have to say, some of the sample images are very impressive (for example, Ed's shots here (link) are awesome!).. it got me wanting to test out my 35L.
I think a lot of people just have out of whack 35L's.. I've owned 3 of them, and finally settled on this one, which, coincidentally came back from Canon service (in Canada) before I purchased it. I like to think this is one is pretty spot on, and is pretty sharp for 1.4.
@1.4 (ISO 200), pushed about 1 stop in LR. Focus obviously on the nose.
100% crop - no sharpening
100% crop - (perhaps a bit over-) sharpened
I think it's entirely possible (and been stated a few times by reputable people) that the Sigma is sharper.. I'm just not sold on QC at the moment. I guess time will tell.