Over the weekend I borrowed a friend's 50mm f/1.8 to see how it compared to my 40mm f/2.8. I'm looking through the RAW files now and I have to say... the 40mm blows the 50 out of the water.
The 50mm is almost never tack sharp and just seems to be missing the focus point. He was having problems with it not recognizing what to focus on using his T3i, and I was having the same issue on my 60D. Has anyone else seen issues like this?
I'm definitely feeling pretty good about spending the extra $50 for the 40mm over the 50mm. f/1.8 would be nice from time to time, but not at the cost of losing focus.