Excerpt: I bought this as an upgrade to my 18-55 kit lens that came with my T1i. I planned on using as my everyday lens. The first thing I noticed about this is that it is much heavier than my Canon kit lens...probably a good thing (better quality), but taking a bit to get used to. In the short time I have had it, I have noticed an improvement in sharpness over the other lens, but haven't done any straight comparison shots.
Pros: Easily Interchangeable, Fast / accurate auto-focus
Excerpt: Use as daily lens started getting error code 99 communication wrote Tamron 8 Aug got email 11 Aug tosend them lens they adjusted Aperture Assy got it back 20 Aug it works great now produces really sharp photo.
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus, Strong Construction
Excerpt: I needed a lens for doing indoor photography at a work conference. The 2.8 worked nicely and I also used my external flash I was very pleased with the photos it took and the cost of the lens made it even better!
Pros: Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight
Excerpt: I was lucky to pick up a used version of this lens for $280 for use with my Canon 5D Mark III (as a general walk around lens).I just couldn't see myself spending $[$] for the Canon EF 24-70mm f/2.8L II nor did I have the money for it.I agree with the other comments here on sharpness. A little soft at 28 + 75mm at f/2.8. But you only need to go as far as f/3.2 - 3.5 and the softness disappears.