I had the VC version for less than a week. The images were extremely soft at f/2.8, but it started to get sharper at f/4.0. I combing through numerous forums and kept reading that the non-VC version was a lot better than the VC version. If I remember correctly, it has something to do with a calibration problem caused by their software; the lens had to be sent in to Tamron to be updated and then calibrated.
I did try to change the fine tune settings on my D7100, but I had no luck in seeing any change. However, if my math was correct, the lens had a front was off by 14mm (front focus).
Of course, as with all things, it's probably a hit or miss with what you'll end up with. You might get a lens that has no problems; or a lens that you want to spike into the ground. Good luck!
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