Yesterday I sold my D300 that I had since 2008 and have taken around 17K photos with it. I sold because for my concert photos I need more ISO and D300 stopped in practice on 1600. I always have looked at the D700, as far as I can see it gives not bad at ISO 6400.
I have alas looked into the D3s, but an nice used d3s here in Norway cost the same as an new D800 (around 4000USD/25000NOK), but an nice used D700 usually is around 1650USD (10000NOK)
Im not into video, never missed it on my D300, so that is not an concern for me, only hope my 70-200 VRI isn't too shabby on an FX compared to the VRII.