Shun Cheung , Sep 24, 2012; 03:20 p.m.
The D600 is essentially the FX version of the D7000, which is 16MP. If you move to FX, you will likely need some new lenses. If you are staying in DX, you might as well wait a few more months to see what Nikon has to upgrade from the D300S. The D7000 is an option, but as you outline above yourself, in some areas, the D600 and D7000 will be somewhat a downgrade from the D300S.