I had a Nikon 28-200G some years ago and when I look back at some of the shots taken with this lens on a D700, I wish I had kept it! In fact I am in the market for another!
Not sure how it will perform on the D800 but don't see it losing anything to the D700. It's small, lightweight and can be picked up for little money.
The "lens snobs" will certainly shun it but I know what I see in print and this lens punches well above it's weight. A great example of how going FF doesnt have to cost the Earth!
Heres a couple of snaps taken with the 28-200G AF.
Also a link here for more info on this lens
Regards, Mark (winter1)