My GF now has my D7000 since I got a D600. I still use it from time to time, and am always impressed with its performance. From a controls standpoint, it's almost exactly the same as a D600. Handy for me. It's a great camera and the 18-200 is an excellent lens.
It's one of my 14 Nikon lenses, all of which work great on the D7000. This includes 2 converted non-AI lenses.
The 18-200 and a Tokina 12-24 (which I recommend) are my only DX lenses. These two lenses and the D7000 make a great travel kit.
The D7100 probably is not worth the extra money for you. I determined that it isn't worth it for me.