Well...no doubt I made the right decision in getting this lens over the competitor's. I got my Tamron 17-50 tonight and whoa is this thing sharp. Sharper wide open at f2.8 than my 50mm is wide open at f1.8. I'd venture to say that it might be sharper wide open at f2.8 than my 50mm is at f2.8. Believe it or not....this first picture is with a very, very slight amount of USM on the eyes. Probably 1/3 the amount I normally do when shooting with the 50 (no sharpening or PP on anything else). This one's just for kicks....we told Brandon to give Gracie (the dog) a kiss and he ran to the gate and tried to give her a kiss I can post the un-eye sharpened of the first if requested, but so far I'm pretty amazed with this little lens. If I can get shots as sharp as that first one wide open @ f2.8, then I'm not sure what else to ask for....oh yeah and it was shot at 50mm where this lens is suppossedly it's least sharp.