I actually just picked up a 2000 Trek 5200 myself. It was only ridden for 4 years so it was in pretty good shape. It's been holding up very well for me as I've been averaging 150+ miles on it per week.
All the parts on it work perfectly still, I have a set of new 7800's and it's comparable given that it is my commuter bike so I have lower expectations of it. Just make sure to either tune it yourself or get it tuned. I'm slowly doing a teardown of it and rebuilding it as I clean everything and replace parts as needed.
The only complaint I have is that even though it is very strong, I do get a good amount of flex out of the frame, a little more than I'd like