I am totally happy with my decision to purchase a D700 over the D3. The pro build of the D3 is very desirable but in the larger scheme of things the D700 is wholly adequate in terms of high ISO capability, frames per second and autofocus capability. To my way of thinking the D700 is a half priced D3.
I have to admit that I added a D3s when they came out but only because I needed the improved high ISO capability for shooting bands in dark bars without flash. In fact I waited as long as I could hoping a D700s would be released.
So now I have a D300-D700-D2h-D2x-D3s lineup of bodies. The D300 and D700 have grips and I am very comfortable moving fairly seamlessly between bodies.
My opinion is that you would never regret aquiring a D700.