60D and Tamron 17-50 (non-VC) AF performance
I just got mine last week, and so far it's been very good at focusing in low light. I also love this lens since the aperture doesn't change with focal length. And as far as noise, it doesn't bother me. In fact, sometimes it makes some,sometimes it don't. Even the handheld shots are great, even though I use mine on a tripod most of the time anyway. I think it's a bargain for the price. I'll have some shots up on flickr soon.
No matter what you're shooting, always keep God in the picture.