Looking for input. I cannot justify all the money ... (
I'm with you. Nothing has worked as well for me as Nikon lenses. Stick with them and you won't be sorry. 200mm seems a bit short to me for BIF but I don't shoot BIF so what do I know? As much as I love my D750, especially for its low light capabilities, again I understand that DX is normally better for BIF than an FX camera. You might be better off putting your money on the best lens and keeping your D7200. Don't forget the deals on used and refurbished lenses that have been mentioned.
I am a new member but long time picture taker. I was using a 80-200 2.8 ED until recently for wild life, mostly deer and an occasional song bird. I bought a 200-500 this winter and have been getting very sharp photos with my D7100 and this lens. If looking for a birding lens you should look at this over a 70-200 2.8 for the increase in reach. The lens is very sharp wide open and the f5.6 hasn't hindered me very much, although it may be a bit slow on Deer. Time and season will tell.
(a regular here)
First, if you do some research, you might discover... (
The one stop isn’t because of limited ISO as in film days, the one stop is for the *POP* of shallow DOF.