I sold my D300s and bought the D600. It was a no brainer as all my lenses were FX and had been since my film days. The main reason I still used FX lenses was that long ago some expert had said that the DX bodies only used the centre - the so called "sweet spot" - of the glass. I guess I kept this in mind as I worked my through the Fuji S2 and S3 Pro, Nikon D200 and D300s. Also I saved enough money on the D600 purchase to buy a D7100 body and with one exception (DX 35mm f1.8) I still use only FX lenses.
Cold weather photography makes a VR lens your best friend. Think violent shivering. :-)