I still consider myself a beginner with a DSLR, a Nikon D5500. My experience with film was with two Canon F1n's. I like the D5500 and don't plan on abandoning it. It's a great camera for walking around and taking shots and casual videos.
Now that I've got a computer that supports Affinity photo shop I'm now hungry for a more serious Nikon for astrophotography and portraits, so weight isn't a consideration, and I've only got one DX lens. The others being FX I use on the D5500. Now, I've gone over the specs and my budget many times and the Nikon that seems to come out is the D800/D800E in gently used condition. Others on my short list would include, D7200, (about the same price new as a nice used D800E)- D750 (more than a Nice used D800E)- D810, (much more than a nice used D800E).
The question is, Is the D800/D800E still a good and viable choice with Expeed 3 processor? I don't recall off hand what the FPS is with the Canon F1n motor drive, but it was enough for what I shot with them.