This lens is my only prime (currently), and it gives me truly sharp and contrast pictures with my Canon 10D, even wide open at f/2.5. Bokeh is great! For indoor, it has to be coupled with decent flash to get good result.
Working distance has not been a problem for me.
Build quality is just great, compared to my other consumer zoom lenses.
This lens seems to retain its value pretty well. So grab a copy for yourself to try it! If you don't like it, most likely you can sell it back at a very good price.