My new D800 has Left/Right AF issues too :(

THIS target uploaded by Fayard works great.  His original post is HERE.

You want to see the difference from front to back which this shows.  The side focus points will always be a little softer than the middle because lenses are always sharpest at the center.  The key is to compare relative sharpness at different distances at the same focus point.

The D800 refurb I purchased a month ago doesn't appear to have an issue, but I don't have any super fast wide angle lenses so the best I could do was check it at 24mm with a 24-70 F2.8 and 24-120 F4.

Most of my lenses required a -8 to -12 to optimize.  The Nikor 50mm F1.4 required the most offset.