>If you could have only a D4 or only a D800 which would you choose?<
>...I think it would be interesting if everyone answered according to their individual needs...<
I would choose a D800(E). As a landscape shooter the high resolution, lack of an AA filter, low fps, (relative) light weight and small form factor of the D800 compared to the D4 all align perfectly with my needs.
>...if you're wondering what my criteria is in case you want to advise me:<
If cost is not a consideration then I consider the D4 the camera most suited to your needs.