Overall a keeper because it's the best Canon can do around this focal length, but I don't believe it deserves rave reviews.
Colors and bokeh are wonderful on both my 1D and 5D. It sits on the 5D most of the time. Great for available light candids, walk-around shooting.
It's quite a bit softer wide open than I expected. Past f2-ish the lens sharpens up. And the vignetting is also surprising - it doesn't moderate until around f4 or so.
I guess you can argue that some softness and vignetting in low light shooting is acceptable, but it's still disappointing,
Paying $1100 for a sharp, balanced 35/4 with nice color and bokeh seems extravagant.