When the D600 was rumored to be $1500 I planed on getting two and selling my D800. The first one in Monterey Bay sold for $2100 and I bought only one. After giving it a complete try, I decided to take it back or sell it for a D800e. I like the D800 better in every way but weight and price. I even like the Best quality, Medium, Fine JPEGs better than the D600 Large Fine ones. The narrow groove in the D600 grip pinches my fat fingers. I can actually hand hold the D800 much longer.
We kept the D600, my wife (second shooter) is very happy with it. The layout and grip fit her hand well. She likes the menus and controls better. The pictures are better than the ones she took with the D7000 and D3.