Does this new D800 spell death for the D3x ? There has been an onslaught of D3x ads for really low prices over the last few days. I can see how this might be, given the capabilities of the new camera. The D3x was never up to the D3 or D3s in low light capability, and neither is the D800 it seems. But it was a great landscape and studio camera. Can anyone see an advantage the D3x has on the D800 ??