Well, after testing both the D600 and the D800. I decided to opt for the D800. I was able to return the D600 for my new D800 which I just got today. Because I am shooting primarily models in studio and interior location, I couldn't ask for a better format than that offered by the D800. Although the D600 is amazing, the D800 allows me to crop after the fact with greater confidence as well as allowing me to choose several crop formats from the onset.
The output is absolutely astounding and the AF is ultra rapid to say the least. I have no from either with the 4 fps High Speed shooting rate. Will be using for my up and coming shoot very shortly.