I do close-up photography, very little actual macro (1:1). I have come up from the beginning and then through the D1x, D100, D200, D300, D3s, D3x, D800E, and now the D810. Of course, lenses are perhaps even more important for this work.
I consider the D810 the finest camera for this kind of work that I have ever seen, better than even the RZ67 MF Mamiya system I use to have. I value the 36MP and would like even more, like 54MP or something. I especially value the ISO 64 in the D810, and the ability to actually use LiveView to focus, which is all I use these day.