Upload & Sell: Off
I have a different experience with the Tam 17-50mm.
I recently picked one up from a FM member, but found it to be quite soft on my 7D compared to my 17-55 is. I was disappointed, because I wanted a smaller, lighter package for ski touring. It weighs 7 oz. less than the 17-55 and is smaller too.
I invested in FoCal (now runs on a Mac!), printed targets on mat paper, lit the target properly and did a round of MA testing. The Tamron came back needing a +20 MA adjustment! I've since done some real world, tripod mounted shots with the 17-55 and 17-50 and they are much closer now. I felt the +20 looked slightly back focused, so did some seat of the pants +10, +15 and +20 MA comparisons, and went with +15.
I'm still deciding if I want to keep the lens.
I was convinced to buy the Tamron because of similar reviews as the other posters here. Anyone else have less than stellar results with this lens? Am I missing something?