I confirmed that my D800 (early run) had a problem with the left side AF. Images were noticeably soft and test charts showed it was really out of whack. I dropped off the camera in Vancouver, and they shipped it to Mississauga, apparently the repair center here doesn't deal with pro bodies that much.
When I got it back, I tested again and see that the left side is working much better now. I need to fine tune the focus, but the consistency between left/center/right is much improved.
I have some test charts posted here in case anyone is interested: http://photokaz.com/2012/08/d800-autofocus-repair-testing/