>It isnt so much the money that is the issue. > >Rather the D600 is priced so close to the D800, I am wondering >if I would be better to Pay the extra £300 and take the D800?
In that case as Stan said you need to look closely at the feature set of both and assess your use to determine the right fit. For me it is all about the weight and size. I was disappointed to see that the D600 isn't significantly lighter than the D800 (I think just a 150g difference) so that is making my own decision a little trickier than I thought. But the D600 is 235g lighter than a D700 - half a pound is starting to look like a significant difference so I'm glad I didn't jump on that body, although it's only 120g lighter than my D300s which I rarely if ever carry into the backcountry, preferring instead a D5100 which at 560g is basically half the weight of say a D700.
Still I'm going for a D600 as it is the lightest FX body and while not as light as I'd like, the move to FX is one I've waited perhaps too long to make and realistically this is probably about as light as FX bodies will get for the foreseeable future. No matter how many additional (or 'better') features the D800 has, if I don't carry it due to the weight then the feature set is moot.
So I just mention this by way of example. whatever your needs and preferences are can guide your decision.