Congratulations on your new D610. I have been shooting for over 50 years with all sorts of cameras and the D610 is the best general purpose camera I have ever owned. The D610 camera body is as solid and reliable as anyone would need unless you frequently expose your camera to rough treatment in the field in which case I'd recommend the D4 or D700. The D800/810 simply creates too big a file for practical general purpose use in my opinion.
I used to own both the D200 and D7000; not any more.
I now pair the D610 with a mirror less Sony NEX-6 that has exactly the same sensor as the Nikon APS-C D7000. The NEX-6 gets carried around everywhere due to its small size but when I get serious, the D610, with its larger format is superior in image quality in all respects than the NEX-6 with the D7000 sensor.