I can understand. Although mine was ok, I sent mine in just to be sure (thanks to Big Country being the trailblazer on this) and they made some AF adjustment as they noted AF discrepancies. This was confirmed as my 600 needed about 45% less fine tune adjustment with Dot AF tune. I knew if they made adjustments it would be better. The camera just needs to be individually touched by Canon as I see it. I was willing to take the risk, betting that the reward would be 10 fold and so far so good. I think those willing to take that risk, too, will be equally as happy.
As a side note, I had AF issues with the 1D3 (well known issue of course) and the 1D4 and once Canon made their adjustments, the "within specs parameters" were made tighter therefore the lenses even sharper. I knew that if they could get the 1D3 AF right, they could do the same for the 7D2.
The 5D3 is definitely an AF beast and makes stunning images. If they make this a 10 fps body, I will be all over it.