I just sold my 17-40L. I'm debating on the 24-70L but some of the focus issues I've read on POTN and FM makes me hesitate.
Did you get a perfect copy new? Did you have to send it in for calibration? Did you have to send it in multiple times?
I could buy a used one and trust the seller's word on it's quality. With the rebate, B&H has it for $1110 new. Used ones are roughly $150-200 cheaper.