Since you've owned both (and anyone else who has...), is the $1,500-$1,700 price difference I see between these on the used market worth it? I am asking because I want to get the latest I can afford (which means the D4 is right out!).
However, the big differences I see are a) video, which I have zero interest in using, b) 1 more stop of ISO performance and c) a deeper image buffer.
My choice is essentially save for a D3s, or get a D3 and use the difference toward a Nikkon 24-70 f/2.8.
I'm trying to position myself as a second-shooter for other photographers, so I sort of need a camera that can do it all...fast burst rate for sports, good ISO for low light (indoor horse arenas, concerts, possible weddings) and full frame (for portraits and personal projects).
If stepping up to the D3s is significantly better than it appears when you write it down, then I'll work to do that.
FWIW, I'll be moving up from a D200, so either one will be a significant improvement.