It's very sharp, for certain, but not as sharp as my 85/1.8. Gets even sharper when stopped down to f4, but that's it, you're not going to see any more change even if you stopped it down more and did test charts. Edge to edge sharpness.
Contrast and colour are on par with Ls I have played with as well as the 85/1.8. Very good.
I use this lens mainly for portraits and for abstracts so the 1:2 isn't an issue for me. I suspect it might be very good for flowers though. Focussing is fast enough on my 1dII and catching moments during events are not a problem.
My only complaint is that the bokeh produced by this lens looks a tad choppy and by far isn't the most pleasing.