I'm going to throw out there that I think Nikon has too many DSLR camera lines going. Think about it:
D3300
D5500
D7200
D610
D750
D810
Df
D4
Do they REALLY need 8 different lines? And it's even worse than that, because the D7100 is still in production, I think, even though the D7200 is out. It just adds to the "DSLRs are confusing", because even buying one is a mess. As a D7000 owner, for example, I'm not sure which full frame camera would be the logical jump for me (note, I'm not planning to make that jump any time soon), because there are too many options that don't seem to have major differences.
It looks like even more when you consider how many other models are still available new.