I'm with you Neil. I also don't like the step backwards in form factor. One of the reasons I love my D300/D700 combo is that they handle the same way. When I go to air shows I like the D300 with a long lens and D700 with a medium zoom. I can swap cameras out without thinking.
If I got the D600, going from one camera to the other would be like patting my head and rubbing my belly and then quickly changing.
Scott Chapin Powder Springs, GA, USA Nikonians Team Member