Upload & Sell: Off
My 70-200 f2.8 II has a very nominal amount of back and forth movement, when I first got it I thought it was farmed, so I sent it back to B&H and they sent another brand new one and the same occurred. It is the only lens of my 15 or so with this "slack", but the results from it are too good to argue with. Does the same on my 5D mkII and 5D mkIII, as well as my 7D.
I think it can be viewed as normal tolerance. At least I tolerate it :-)