Glad to read your perspectives. I wonder if the optical formula for the mf version is the same as it is for the af? I saw a few of the af ones on eBay. If pushed came to shove, I could live with an af one, but it would be cool to get one in Adaptall II.
I'm also a big fan of the Tamron SP lenses. In the past I owned a 60-300/3.8-5.4, a 90/2.5 macro, and a 300/2.8 LD IF. Sold them off over the years, but have since re-acquired two (!) 60-300s and a 90 macro w/teleconverter. Got my sights set on one of the 300/2.8s that come up on eBay from time to time.
I used to own a Vivitar Series 1 28-90/2.8-3.5 that rarely came off my camera, I used it so much. Great lens, and I've been thinking about picking up another one for my Nikon system. Then I ran across this Tamron. I'd love to get one, but it's hard to justify the $600 (new) expense compared to the $50 or less that a Vivitar 28-90 typically sells for on the bay.
Michael