Upload & Sell: On
I would go for a D3 with the Buffer Upgrade over a D800 any day. BUt it depends on your usage. I am a pro and shoot everyday. Right now, my D3 has over 375k actuations and it is my "go to" camera over my D3s. The only negative, to me, is the D3 is a dust magnet (it doesn't have the self clean that the D700 does-not sure if the 800 has it)
I had two D3 bodies one of them had the buffer upgrade and it was not faster plus I got very few extra shots.
It also had over 375k shots but only needed cleaning a few times
even when using the 80-400 (dust pump) for MotoCross.
All I can think of is that you must be letting in dust when changing lens,
and now you knock it off with in camera cleaning.
I am not knocking the D3, but I would take a D3s, D800 or D4 over it any day..