If you dont take a lot of telephoto, I would suggest you get the Tamron 17-50mm glass. Very sharp and worth for the price you pay.
Imagine your 18-200mm glass is set at 200mm, it is quite challenging to take shots w/o camera shakes. Most of the time, you either use a fast shutter speed or mount the camera on a tripod to counter the problem. But then again, using a fast shutter speed and mounting on a tripod may not be possible in some situations.. Personally I'm speaking from experience because I use a 18-200mm glass as well and I seldom/try-not-to shoot telephoto...
Aiyoh where got xiong =p You try 1D3 + 70-200/2.8IS + 580EX2 all day long then that one is xiong =p. But seriously, good all-purpose travel lens - but the image quality suffers a bit.
5D Mk II | TS-E 17L | 17-40L | 24-105L IS | 35L | 85L | 70-200 f/2.8L IS | 100L Macro | 580EX II
the sigma 18-250mm is out, about 900 plus. I think it has won a beginners lens award or something.
Has anyone bought or tired out this lens.