D800 or d7000?

I am a happy owner of a d7000 however I am considering replacing this with a full frame camera and the natural progression appears to be the d800 as the DX mode would be almost the same as that on the d7000.

The reasons for changing are primarily to do with landscape photography and dynamic range and this is root of my dilema.

From what I read it would appear that the d800 has pretty well the same DR as the d7000 (14.4 v 13.9) - is this correct? if it is I doubt that I would be able to see any difference and would still need to resort to multiple shots and HDR to cover the DR in many scenes.

I possess and 10-24mm DX lens which provides a wide angle and I am unclear if i would get better with the d800, though clearly my 35mm Shift would be much better. I would need to replace the 10-24mm with something more suitable for the FX.

I would also like to know what advantages the Expeed 3 provides over the Expeed 2 that is in the d7000.

Hopefully these questions are sensible - please convince me that it is a good move to chnage to a d800

Iain Morrison