We stayed in this apartment on the 4th July long weekend and it was great! Everything we expected from the photos and more. The location was excellent with a walk to everything (metro, capital bldg, restaurants, even national mall if you don't mind walking) and the free use of the metro cards was awesome. The apartment had everything we needed for a family of 4. The hosts were lovely and went out of their way to provide us with extra little things to make our stay more comfortable (eg. Stroller use). The little touches that made our stay more memorable included fresh flowers and fresh bakery treats on arrival, use of the metro cards and a lonely planet guidebook. I also loved that there was stocks of shampoo, conditioner, laundry detergent and suncream as I had forgot to bring most of those things!
As this is a basement apartment, expect some noise from above, and you will hear the early morning pitter patter of little feet. This didn't bother us as we have small children of our own and as we were sight seeing we were up early anyway.
Overall we had a wonderful time in DC made better by staying in this great apartment.