One caveat about GW - if you don't take the metro, driving there is stressful and parking is either difficult to find (street) or outrageously expensive ($15/two hours in garage). I'd also suspect that choosing GW for your PCP might limit you to GW for your RE. You might want to be sure to preserve your free choice of clinics. I'm not sure why PP says it would be pain in the ass to get a referral to an RE from your PCP. I have not had that experience.
Also remember that the state your PCP is in determines which radiology facility you have to go to. When you get pregnant, you will have to get your ultrasounds there, so it matters. If your PCP is in MD, you will be bound to Community Radiology, which I don't recommend. I actually switched to a PCP in DC just so I could go to Washington Radiology, which is much, much better.
Sorry I don't have a recommendation, as I have actually not seen my DC PCP yet.