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Regarding the D800 DR. If you are at ISO 1600 or above most of the time, the D3s is the same or better (chart here, or see dxomark).
For me, I would lean towards the D800 for the body size alone (otherwise the D3s), but as yourself and others have commented that may not be a consideration depending on the photographer. So in the balance reading all your comments my vote would be the D3s.
normally if you are shooting at iso 1600 and above its because the light levels are low so the lower DR at these levels is a mute point in my opinion. There scene probably wont encompass more than 6 f stops anyway. If you are shooting at high iso just to increase shutter speed then thats a differrent consideration altogether and you are probably a sports shooter so the D3s or D4 was made for this role.
for anything else the D800 has massive advantages over the D3s.