I started with a Nikon D50, so my D80 was an upgrade. I don't have a bad thing to say about the D80 it is just a wonderful camera. The D200 has metal body and the D80 is plastic, but I do not hold this against it, the D80 has a nice solid feel in your hands. The only very very slight criticism is a slightly red / maroon cast to photos taken in medium light with auto white balance. This is easily correctable with custom white balance and a gray card. I like the larger review screen and slightly improved control layout. The D80 doesn't make my D50 feel like rubbish, I still use it, just the D80 is better.
Go for it, you won't regret it.