My wife and I had an excellent stay at the apartment on 21st and P street. The apartment is spacious, has a full kitchen stocked with everything that you need, has a full sized refrigerator, several hair dryers, iron and ironing board, as well as access to a washer and dryer. The wireless speed was very good and the television is more than adequate.
There are several very good restaurants nearby as well as small grocery store that has a good selection of food as well as beer and wine. You're just a few blocks from the metro so it's very easy to get to and from the airport. I'd recommend getting a Smart Card...you save on the fares.
Our requests for more laundry soap were met almost immediately. The management of the apartment was excellent. i guess the best recommendation is that we'll stay here again on our next trip to DC.