The stay at the apartment of Carolina and David was great. We really enjoyed our time there.
The location is very good. Subway (from DC Airport and to the center) quiet close, 14th street with all restaurants (I can recommend Le Diplomat) within a 15 min walk, center if you want to walk around 30 min and the best beer garden in the city just on the opposite of the street.
The apartment itself was very clean and comfortable. Exactly as shown on the pictures. And the bed was relaxing.
Pleasant is that you have your own bathroom, too.
Further they provide some tourist guides which were very helpful during our stay.
The contact was always perfect and quick. Check in and out was very flexible.

For the next trip to DC we would choose the apartment definitely again.