Owned all 3, but wud oni settle for either efs17-55 or sigma,
Wun talk too much bout IQ as it's all over the net even YouTube comparison,
So my Tammy din last me more den a week, it was good, everything was good,
But The thing bout Tammy 17-50 is dat the feel on my hand really isn't want I wanted but it's really extremely light, too plasticky,
Sigma n canon ones feel very good, esp canon,
For me, I had never printed any of my photos, but all photos are in my iPad,
Really couldn't tell which pic comes out from which lens in my iPad, but than again I do not earn $ from my equipments,
Since there's sigma n Tammy to choose from, sigma would b a good choice as it's probably bout the same price now,