It depends on what you're there for. Are you there to network or to listen to the speakers? Are you comfortable with black-tie affairs (I'm guessing that that's what these are)? If you're there to network, you might want to be as visible as humanly possible; if you're there to listen, skip the black-tie and go find a little place in DC to eat. There's a Japanese/sushi joint off of Dupont Circle that has fantastic food and nightly karaoke, if that's your thing.