I notice from another thread that you had a bad version of the 24-105 L too, which lens Canon could not find anything wrong with with 3 returns for calibration.
So you're ranking is that the 24-105 L was worst (consistently?), the 17-85 was inconsistent or consistently unpredictable or consistently average - (which seem like 3 different things to me) and the 17-55 is good.
Curiously you also cannot find any difference in picture quality between the 70-300 IS and the 70-200 f2.8 L IS.
I cannot get good pictues with an average or poor lens.
Or even sometimes with some rather good lenses it seems. And of course we all know of some extraordinarily good photographers who seem to manage to get amazing pictures with very modest equipment indeed.
Well, I guess some people are just very unlucky with their purchases.
At any rate I'm glad you found something you like, the 17-55 certainly does look like a very nice lens.