I generally find the restaurant reviews from the Washington Post to be more reliable than those in The Washingtonian.

Most of the cheaper places I can think of around both Dupont Circle and around the Convention Center are more ethnic. The Convention Center is a short walk from Chinatown which has relatively few Chinese restaurants nowadays, but quite a restaurant strip along 7th St. There's also Busboys & Poets on 5th, which has a fairly diverse menu and a iively vibe.

I'm quite fond of Teaism, with several local branches. There's one on R, just off Connecticut Ave, which is near Dupont Circle.