Originally Posted by FstopBMW
I have the Tamron 17-50mm 2.8 and its super sharp. I would think that the Full frame version would be just as good
Hope this helps!
I do appreciate everyone's comments in regards to this...lots of praise on the Tamron, not so much on the Sigma.
After my other research, I believe both to list rather good details in the pics, although there are some issues about the edge of frame distortion at the the full 70mm setting on the Sigma. Needless, I chose the Sigma specifically for the focus speed. Everything I see has stated that the Tamron takes an extended time to focus, which limits some of the usage for this lens that I was going for. The Sigma's focus speed was on par with the Nikkor...which should fit the bill.
I should have this in a couple days...we'll see if I made the right choice or not.