The D700 split into two different cameras: the D800 and D600.
Yeah i guess, but I'm betting most d700 shooters would have preferred a d700s: 7fps, 24mp, solid build.
What they got was either: pretty much the same camera [d600] with lesser build quality but good amount of mp.
Or a complete beast [d800] whilst great for certain users, it's a step backward in fps and too large file size for others.
For sports, event, wedding or wildlife photographers already using a d700, I wouldn't consider either of these a great upgrade. Maybe the d600 for a 'slightly' faster shooting speed and more mp but then you lose the tank like build that the d700 was known for.
I think all three of those cameras are likely able to withstand rougher treatment than most people will deliver. Then again, I've seen some treat the D700 like it was made of porcelain with it wrapped up in a plastic bag whilst they were outside shooting. Go figure. Search on youtube for the comparison between Nikon and Canon where someone tries to burn them with a blowtorch.