I find the focus rather good actually but of course if you use all 51 focus points, the camera may or may not focus on what you intended. There are lots of options and it takes practice and a clear head to understand them all. The latest firmware, announced at the same time as the D700, is said to improve the AF performance. If, for whatever reason, the focussing is consistently off with particular lenses, you can fine tune it.
The 70-200 is a great lens on DX camera but the edge performance is decidedly off on FF. It's almost as if there is excessive curvature of field and the lens has been optimised for DX use even though it is, in theory, an FX lens. Perhaps it should have been sold as a DX lens.