We visited the Large Zen boutique in Washington with four collegues for two nights. This apartment in the souterrain of a beautiful house in a charming neighbourhood of Washington is very tasteful furnished.
Good quality kitchen; superb bathroom; unfortunately with toilet in bathroom, which is less comfortable with friends.
The instructions to find the house and get into it, worked out perfectly.
Unfortunately we did not have enough time to discover the neighbourhood, but we walked around at night and it seems to be safe.
Parking permit so near downtown Washington is a confortable luxury. We did go by car in town because short of time; but public transport is very close the apartment, as are several food stores.
Sight seeing tip: do Washington on bike; it is safe, fun and easy to do all memorials and hot spots in one day!