I think I'm also right in assuming that, on an f2.8 sensitive focus point, an f1.2 lens would focus at 1/3 x DOF at f2.8, and would therefore be no more accurate than an f2.8 lens?
Thanks for clearing that up.
AFAIK all of Nikon's focus points are f5.6. This would mean that an f1.4/2.8 lens...