Now i have read all the reviews i could find on this lens, but ended up buying it anyways. mostly because of the pros. like sharp images, have actually not seen that much CA, if any at all.
My budget dont allow canon "l" or other quality marked lenses, and this was cheap.
But the lens impresses me, have had a lot of good shots, that i cant put a finger on. i manually focus mostly, but i can se the problems if using the lens for fast moving shots, at auto.
My photografer friend that buys lenses for easily 2000$ + actually didnt believe me when emailed my test images to him. he found the lens quite usefull, not saying that he would exchanges his own for it.
tested this lens against the Canon EF 75-300mm f/4-5.6 III USM which is marked at 260$ in Denmark, and the tamron won without a battle. so this lens is gonna end up in my collection, until the money for the "l" lenses starts showing up on my paycheck.
another thing. dont know if i did just get lucky, but the build quality is kinda good, melts good with my 350D, the rubber around the focus ring, feels good, and the zoom, and focus runs smooth. one minus though is, the macro butten i hard to turn on or off if the lens is zoom close to the 180 or 300 limit, and if the focus is at max. but you get what you pay for.