Just this week received my first tamron lens and I couldn't be more happy with it. Autofocus is fast and accurate and VC works great. Build quality is very nice as well. I have zero regret switching from my canon 70-200 F4L IS to it, especially when you consider the money savings vs the F2.8 IS II. I'm actually now thinking about saving for the tamron 24-70 VC next because of how happy I am with the performance of my new 70-200 VC.