Okay, so many of you may have seen my previous post asking if I was crazy to give up my "L" glass in favor of some primes and a wide zoom for my 30D. At the time, I was thinking about ditching a 10-22, 24-70, and 70-200 F4 for a 17- 40 and some primes. Well, one lens that I forgot to consider was the new 17- 55. Has anyone switched to the 17-55 from a 24-70 on their 1.6 body? I've read a ton of reviews about this lens, and from what I can tell, the optics are as good as, if not better than, the 24-70. The only downside (not including the whole EF-S vs EF debate) is that it's not "L" build quality, and it tends to suck in a little dust (which really is more of a nuisance than anything else). Do any of you have both lenses, or has anyone used both extensively? Would you recommend selling a 24-70 in order to get the 17-55?