>I don't know if I would go with "poor choice", as we were happy with 6mp all of 4 years ago, but yes, it seams the only caveat with this camera compared to DX would be resolution in crop mode.
The reason I call it a poor choice is exactly why many *were not* happy with six MP. When shooting birds, it is often necessary to crop by 50% or so, *after* the shot is taken. You just can't get close enough sometimes. If you are starting out with 5 or 6 MP, you are left with a file that won't print big without losing quality. Two or three MP just won't cut it.
And don't forget, even if you *can* get close enough with the D700, the larger-than-DX-crop area of your frame will not be as sharp with FX Nikkor teles (the best ones are all FX). When shooting DX with an FX lens, only the sweet spot in the middle of the lens is used, providing edge to edge quality you just can't get any other way.
Still, I'm gonna jump on that 24 MP full frame D900 the second it comes out. Okay...who am I kidding. I'll buy a D700 when the NAS takes me over...but I should at least pretend to fight it for a while =)