So I took the dive today and bought my first "Tammy" Tamron 17-50 F2.8 VC. So far it was worth every penny of it. A lot of folks are concerned about front focusing and back focusing, but for the last few hours and the 20-30 pics with it there are no issues what so ever. The VC vibration control is quiet amazing and very comparable to the IS image stabilizer on Canon and the VR vibration reduction on Nikon. Also another point of concern about this lens the AF noise; my personal opinion, unless you are shooting pictures in a library, you won't even notice it. The AF noise is very quiet for not having a sonic motor like premium lenses. But to sum it all up I am really glad I bought this lens.