I bought this lens 3 weeks ago, it performed flawlessly and met my shooting requirements and expectations very well. It is a well-designed superzoom lens for walk-about purposes, but don't expect prime-lens like miracles, it's still a very very competent one-for-all Jack-of-all-trades general purpose lens except one sore point...
This lens may have an inherent problem (or I may be that unlucky one-off guy) that many Singaporeans may not be aware of. I bought the lens and used it in Liverpool, Manchester, Paris and very recently, Tokyo. All went very well except in Tokyo.
When I was in Europe, I shot indoor most of the time (in museums), the problem did not show up. And I was mightily pleased with the versatility and results of this superzoom lens.
But when I was in Tokyo, the weather was cold and the temperature could drop below 4°C. That was when the problem showed up...
The Tamron lens contracts quite a bit, to a point when the lens' contacts may fail to make contact with the camera (mine is a Nikon D90);
When that happened, the autofocus dies, even below F5.6. And the camera shows F - -. That means "no lens detected". Although I could fix the problem by unlocking the lens and then re-locking it. It happened so often that it became quite a frustrating experience. But the lens continued to deliver photos as expected when it worked. I was told JEL (The service centre) can fix the problem.
This lens comes with a 3-year warranty. If you are shooting mainly in Singapore, this is not an issue.
Best wishes and happy shooting!
Oh! By the way, this lens is CERTAINLY BETTER than the Nikkor 18-200mm VR DX lens I once owned. The VC (vibration compensation) works like magic! Even at 270mm zoom, it is rock steady! It beats the hell out of the 18-200mm Nikkor lens, in my humble opinion, and I am NOT advertising for Tamron. I sold my Nikkor lens just after 2 months of use. It (Nikkor) is a soft soft lens.
Eddie