Tamron 28-70mm F3.5-4.5 44A

     On the T2i it is difficult to access the aperture ring w/out accidentally nudging the zoom ring.  I've heard some say that the lens feels cheap.   I disagree.  It does have some plastic on the exterior but it it solid internally.  Focus dampening is excellent.  I've done some quick testing, mostly at 70mm.   This is a close focus lens.  It focuses closer at 70mm than at 28mm.  Resolution tests on this lens suggest it is sharpest from 50mm to 70mm from f5.6 to f11.  Those tests also suggest it is somewhat soft at 28mm wide open.   I agree with those findings.   Those tests suggest that it is soft in macro, but I disgaree.   I found it to be quite sharp at 70mm wide open in macro range..   

It is a little soft at 28mm f3.5.  That's okay as it was never meant to be a pro lens and it is sharper than many 28mm primes.  It is capable of excellent images.  Color rendition is accurate.  Fringing is well controlled.   Contrast is excellent at all settings.  Bokeh fringing is well controlled at 28mm but quite noticeable at other focal lengths.