With the help of our forum colleague Frank in Singapore, I was recently able to acquire this lens to (almost) complete my collection of all the Tamron SP Adaptall-2 MF lenses. I'll have more to say on that subject in the future, but I wanted to share my first impressions of this lens and post some images, as it is not very commonly found.
http://www.pbase.com/jamesk8752/image/112298946.jpg
First of all, it's big! It has a filter diameter of 82mm, weighs 880 gm, and is 87mm in diameter x 112mm long at its shortest (170mm extended).
http://www.pbase.com/jamesk8752/image/112298943.jpg
The front element is 70mm in diameter!
http://www.pbase.com/jamesk8752/image/112298944.jpg
Second, it's beautifully built, solid and with a smooth zoom action. One novel feature is a two-step zoom friction setting, rather than a simple zoom lock. It *is* heavy, but it balances fairly well on my K10D (not so well on my K-m...).

Third, it's a pretty good performer. On my K10D (which is set up for MF with a Katzeye split image screen), I found it very sharp even wide open at 28mm; at 50mm and 105 mm it is somewhat "dreamy" wide open but it sharpens up very nicely when closed down one to two stops. I like the bokeh; while it can be a little bit "nervous" in some situations it is a lot better than I've seen from some other zoom lenses I've used.

These representative images were shot in 4-star JPG quality on my K10D, adjusted for exposure, resized, and slightly sharpened in PP:
http://www.pbase.com/jamesk8752/image/112298947.jpg
http://www.pbase.com/jamesk8752/image/112298948.jpg
I especially like the bokeh in this last image - very smooth and creamy edges on the OOF white flowers in the background:
http://www.pbase.com/jamesk8752/image/112298949.jpg
So that's my most recent lens acquisition. My last SP is on order now; it's the SP 90mm f2.8, which I already have in the Pentax AF mount version. The Adaptall-2 mount version has a different optical layout; it will be interesting to compare them. Stay tuned...
--
Jim King - Retired Colormonger - Suburban Detroit, Michigan, USA; GMT -4h (EDT)
Pentaxian for over 45 years.
http://www.pbase.com/jamesk8752/image/52329943.jpg
* * * * *
A fanatic is one who can't change his mind and won't change the subject.
- Sir Winston Churchill
* * * * *
The difference between genius and stupidity is that genius has its limits.
- Albert Einstein