I don't believe the D600 is superior to the D700. If you go to the Nikon USA site and select sort by featured, it sits below it. Yes it has more megapixels and wider dynamic range, but a newer camera by four years should have. The D600 can shoot @ 5.5, the D700 with grip can shoot at eight. Correct me if I'm wrong but I believe the D600 can't shoot uncompressed 14 bit files unless it is tethered. I also like the older 3 position focus selector switch. My guess is that if you want to change from single servo to continuous, it's in a menu? Then there is the build quality, and the dust problems on the D600 sensor (reported by more than one site, wow Nikon needs to get its act together! With the D600, D800 problems I'm glad I have a D700), (Build them cheaper and people will still buy? Is this Nikon's new thinking?) Don't get me wrong I love Nikon, just surprised by the recent camera problems. I would have liked to have had a D800, but now I'm not so sure. And the only true replacement would be a D750 or D900 with 16 MP, ect.
May Your Day Be Happy And Full Of Beautiful Images D.H.R.