This is fast becoming my favorite lens. It's more versatile than one might think, good for people, low light, and macro-ish shooting. (I use it on my 5D).
The shallow DOF and quality of blur with this lens blows me away the more I use it. The lowlight ability, combined with my 5D's high ISO ability, makes it my lens of choice for lowlight people shooting.
It's very cheap for the sharp, high quality pictures it can deliver too. It's great even at f2, but at f2.8 it's already at its best pretty much!