There are several threads going around this topic.
Simply put, I don't expect f/16 to work very well due to diffraction limits. Diffraction will be a bit of an issue at highest aperture settings, but by f/8 or so it is not a factor. You'll need to decide how to trade off depth of field vs. diffraction.
I expect D800 images to have a bit of a different look. The in focus area at f/8 will be sharper than anything you have seen from a conventional DSLR. At the extremes you may lose a little with wider apertures, but part of our technique is to make the sharp focus areas very sharp and blur secondary areas.
But before you get concerned, look at the depth of field with your best landscape images and see what would really have happened at f/8. I think you will find the edges of depth of field are willingly traded for a sharper subject.