You have to understand that after I dropped this I almost chucked the camera, lens, tripod and assorted bystanders into Lake Superior.
So I was rather unhappy at the time. Take my post here as being an indication of that.
The build quality of the lens is less than stellar. (In retrospect, however, the camera and lens did fall farther than I thought at the time.) But optically it is truly wonderful.
I paid $140 or so to get it fixed by Tamron. I'm not sure it even took 2 weeks to repair. (Including shipping time.) Works great. They did an adjustment and I think it might be sharper than it was before the incident. (I could also be crazy.)
Just bought the Tamron 17-50 f2.8. I like the 28-75 a lot. I like the 17-50 more.