I think this is kind of a hard question to answer, it really depends on your preferences. Obviously, DC is a far smaller city. The city doesn't have the international trust funders that you will find in NY,LA, Miami. It's working/middle class immigrant population tends to be centered in the suburbs (with the exception of a couple small pockets of Latin Americans and Ethiopeans).
The city does however, have some very well educated, professional foreign nationals associated with the embassies/NGO/international organizations. They tend to come from wealth backgrounds, be cultured/intellectual/hard working and interested in "do gooder" causes/world affairs. In general, these people tend to be socialize in Georgetown/Dupont and the K street clubs. Like all yuppies in the DC area, they are at least as likely to live in the suburbs as the actual city.
Beyond the dating scene, you should think about whether or not you are ready to leave the NYC lifestyle behind. My experience has been that people who try to hold on to their NYC lifestyle in DC, end up hating the city. The ex-NY'er who tend to like it were either looking for a change of pace or really interested in politics/public policy.
DC is a good city and has a lot of things going for it. But, its strong points are different than NYC. Probably the best way to see if it is right for you is to come down for a weekend and try it out.
Last edited by Caymon83; 01-16-2010 at 04:51 PM..