I know little about the STF other than it's $ and I've seen some beautiful images taken with it. I'm always watching for a deal, but don't think it will ever get down to what I'm willing to pay. I really haven't seen it used a lot with indoor portrait work where you have the control to do other things. More for outdoor type portraits - people and nature.

The 200 f/2.8 is one of my favorite lenses and I use it often. AF snaps on lock and it's sharp as any.

I never find myself looking for something in the 85mm range so that lens has never held my attention. Maybe if I did portraits...?

Terry