24-70L returns

After much deliberation I've decided to purchase the 24-70L. From my research on these and other forms it seems that there are quite a few less than perfect copies of this lens about. It appears that many purchasers return their lenses for various "quality" reasons.
My question is with respect to these returns. Are they returned to normal stock and offered to the next unsuspecting buyer? If I order from B&H is there a high probability that I will get a dud? Maybe somebody out there can enlighten me! I'll be ordering via the Internet and would like to minimise the chances of receiving a poor copy.

I haven't sent anything back yet, but I just ordered this lens from B&H.
Unless I'm mistaken, when you send something like this back, it actually gets repaired and the same lens is returned to you once fixed, it doesn't go back into stock and you don't get a new one, unless the old is beyond repair for some reason in which case I would think it gets scrapped and they ship a new one out to you.

They keep sending the same one to the same person until they are happy

(if this was the kit lens, it would be curious, but for a fantastically expensive lens, it's incredible).

Graham

My "new" 24-70L came with the focus switch in manual poition which kind of made me wonder since every other new lens I've bought had the switch in auto.

My new 17-40 was a little soft at first, but banging it against the table a few times solved the problem. Return was not req.