BES,


If you cannot afford an L buy the Tamron. The AF is not as accurate as a USM lens. It's the mechanics of the body to lens AF link. If you require exceptional AF accuracy with the lens wide open (f2.8) and rely on this for income then you may want to reconsider. Otherwise, the IQ is exceptional. I could not afford the 24-70 f2.8L but even though I do have the Tamron I recently (last 6 months) purchased a used "28"-70 f2.8L to complete the 17 - 200mm f2.8L "triad" for my 5D FF. I really like the big L with it's red stripe and silent accurate AF. It's shall we say "fabulous". But, I still really liketo use my Tammy 28-75 f2.8 Di on my 5D and 40D. It's light, it's accurate enough, and the IQ/bokeh is still IMHO in a league of it's own. For me, this Tamron will always be an "iconic" lens.


Mark E, was right...........[]