LeanderL: I handled a D750 yesterday for a couple of minutes. I was considering it to replace my D700. But that is not going to work for me.It felt so much smaller and less comfortable in my hands. Also the finder seemed much dimmer and smaller (don't know if that is only my perception).In all the D700 is in a totally different class. So I am looking at the D810 again, even though the 36MB files are a bit too much for my taste.
I've been looking for something to replace my D700's and, when I saw what the D750 was, bought a D810. It's early days but I haven't been disappointed so far. I used the 810 alongside a 700 at a wedding last week and, when post-processing, I have been surprised how much nicer (less noise, and obviously far more definition and a greater ability to crop) the D810 files are. So much so, in fact, that I'm thinking of selling both 700s and buying another 810. File size is a bit of an issue but the advantages brought by the newer camera in terms of picture quality significantly outweigh this issue, at least IMO - YMMV. One thing - a Sigma 35mm 1.4 doesn't seem as sharp on the D810 so I'm going to have to look into that. One other advantage that occurs to me - the quieter shutter is a godsend!
Foliobook is OK-ish, but it keeps crashing my iPad (version 1 of the latter, admittedly).