Hey Betty,
Thanks for the kind words. I forgot to mention in my first post, there's a great site on the net that has lots of info on the manual-focus Tamrons:
adaptall-2.org
A bit of info on the race car: that pic was taken at IMSA's last race at Riverside International Raceway back in 1986. It was zooming past my position at over 200 mph when I took that shot. Impossible to focus on a moving object at those speeds, so I would prefocus on a spot on the track, dial in a sufficient amount of depth of field, and trip the shutter at just the right moment. Tricky.
The only AF Tamron I have direct experience with is a 24-70mm Aspherical, which I bought new back in 1994. It's always taken good pics, and shows decent sharpness with my DSLR. But I can't really comment on their more recent offerings.
As for picking up these old Tamrons, a few words of advice: be patient. Wait for the auctions and avoid the Buy-It-Now listings. My experience is the BINs are always over priced, and you can usually pick up a clean Tamron lens for much less than what they're asking in the BINs. Back in 1985 I paid over $300 for my first Tamron 60-300. Sold it several years later, but recently acquired two more. Picked up one without mount at a local camera shop for $40 and picked up the other one from an eBay auction for about $20. Only reason why I bid on the auction was because I wanted the mount it was attached to. So I got my 2nd 60-300 for the price of the mount.
The 24mm f/2.5 can be found for reasonablle too if you're patient, but the same can't always be said for the Tamron 90mm macro. It has an excellent reputation and is in pretty good demand, so you can expect to pay a pretty fair sum for one, but still it's an outstanding optic and well worth the price, in my view. I also have a Micro Nikkor 55mm f/3.5 and one of the legendary Vivitar Series 1 105mm f/2.5 lenses. My Tamron 90 outperforms both: it edges out the Vivitar, and is equivalent in center sharpness to the Nikkor, but blows the Nikkor away in corner sharpness. Oh and by the way, in a pinch the 60-300 does a decent job with its macro capabilities too. It is surprisingly sharp.
Back in August, I tested the macro capabilities of all four of the above lenses and wrote an article about the test for my blog. If you're interested, you can read about it at the following link. Scroll about halfway down.
Michael Sez