Is the d4 better at focusing than the d800?

John Cote wrote:

I hate getting involved in a fight like this but this is just insane. I am a full time professional motorsport photographer. I spent hours aiming long lenses on both the D4 and D800 through holes in the fence above the safer-barrier at Indy this year shooting cars and groups of cars coming at me at 220+ mph. The D4 with the same lens, same settings (close as you can get) and same technique could follow focus and give me consistently focused shots in a burst from far to close. The D800 was hit and miss at best.

You can tell me that this is not scientific but I don't have time to shoot test charts and brick walls. I have to produce pictures. My technique is pretty decent and my knowledge of how to set up a camera is pretty OK too. My customer wants to see motion and read the decals at the same time. The D4 and D3 will do it. The D800 won't. I never used a D700 so I can't tell you.