Great location - could walk everywhere and the Metro station was very close by after a day of museums when our legs couldn't walk any more.
Greg was very available, meeting us when we arrived and texting us with updates throughout.
Apartment is as advertised. Comfortable and clean. Great base if you plan to be out and about all day (which we were). Five of us stayed - two queen beds and two air mattresses that I was assured were comfortable. Sheets, towels and blankets for all, and a washer/dryer which was welcomed by those in our group who had been traveling for a number of days before we arrived.
Would definitely stay there again if visiting DC.