I bought a Tamron 28-270 I think it was, for $100 used in 2006 or 2007 I think it was, and used it on the Nikon D70 and D2x, 6-MP and 12-MP cameras respectively. it was not as sharp as I would have liked, especially at the longer zoom settings, and so I passed it along to a nice lady who loved it for shots of her grandkids, using her D50, another 6MP d-slr, one that had very punchy SOOC JPEGS. But that was the 28-270! I own a Nikon-made 28-200 G, their second 28-200 model I believe it was, much smaller than the earlier 28-200 design. On 6MP D70, the 28-200 G was adequate; on 12MP D2x, I thought the 28-200 G was inadequately sharp.
Tamron was the company that actually _invented_ the triple-extension barrel, according to an article on the 28-200 in Modern Photography, and written by then-editor Herbert Keppler. The triple-extension barrel is part of what made the 28-200 so popular. Keppler himself owned and used and liked the 28-200 Tamrons. It is a super-convenient lens! 28mm to 200mm, with no lens swaps. He liked the fact that lens swaps were simply not needed when this lens was the one being carried on a film camera. Tamron introduced the 28-200 concept and went thru multiple iterations of it, according to Keppler, and each one was better than the prior version.
