I picked up the 17-55 F/2.8 and am looking forward to using it. I'll see if I can handle the missing gap, which as patham mentions I can move around to cover it.

Are there any general rules around depreciation of lenses? I'll start looking around for similar pricing, but wasn't sure if there were good guidelines around selling a lens that is still pretty new.

I was tempted to keep the 15-85 when I wanted 1 lens to walk with, but figured selling it would be better and I can look at a prime or macro lens for the future.

Thanks again for the advice,
Eric