I just finished up a Masters degree there and took a lot of the same courses with a lot of the same professors that the med students have. I'd say I really really enjoyed 70% of the professors I had. The other 30% I disliked mostly because they all had very thick accents and poor English and did not seem to care that we couldn't understand them. While the faculty is ethnically diverse, however, the student body not so much. If you're looking for diversity among your peers or patients, you're not going to find it there.
I have a lot of friends in med school there and they all really like the program. It is expensive, but when you're already paying $30,000 a year, what a few more grand? I've had a great experience there both as a student and a research assistant in their cancer center. Also DC is a GREAT city to live in. I'm originally from LA and while I'd be crazy not to choose a state school if I get accepted to one, I'm really going to miss DC.