- Like what you've got: stick with it. There's nothing particularly wrong with the D7200.
- Dislike what you've got: You have two basic choices: (1) move up to the DX Pro body upgrade (e.g. D500); (2) move up to FX.
Which should you do? Here's the simple guide:
- Choose #1 if you're happy with what you've got in terms of camera and with DX in general but want to upgrade simply to update your equipment and get better body quality and performance.
- Choose #2 (move up to FX, most likely the D610 or D750) if you're now serious enough that only the best possible image quality will do for your next camera. Be prepared to have to upgrade your lens set, too, though, especially at the wide angle end.