We stayed at Steps From the Capital for three nights. Marina was very friendly and helpful at the time of check-in, providing much useful information. In addition there were materials and maps in the apartment that afforded helpful information.
Overall, the apartment was more than adequate, but is showing some signs of wear and tear… nothing that affected our stay in a negative way. The best part was the location -- only 2 blocks to the Capitol Building, and close to the National Mall, memorials, and monuments. A perfect place to use as a base while exploring DC. The apartment is very convenient to all forms of public transportation. Plenty of good restaurants in the neighborhood, as well as a few blocks away. (For great Mexican, try Tortilla Café, featured on Diners, Drive-Ins and Dives!)
Considering price and location, I can recommend Steps From the Capital.