Matthijs Claessen , Apr 20, 2010; 07:22 a.m.
50/1.4 at 1.4 on a 40D is here.
60/2.8 at 2.8 on a 40D is here.
Both are pretty good, the macro probably a bit more sharp if you pixel peep and the 50 can blur a little better if that's your prime requisite. But in the end both are good for your purpose I'd say.
Personally I can only vouch for the 50 which is pretty good image quality though I'd love it to be a little bit tougher.