I would definitely recommend Cesar's place for anyone visiting DC. The house itself is very well equiped and comfortable.There are plenty of nice restaurants, cafes, bars and shops in walking distance (5-10 mins) . We really enjoyed the Mexican restaurant around the corner.
It took us about an hour and a half to get there from Dulles airport but the journey was very straight forward. Once we were there we either walked or rented bikes from Capital Bikes to get around. It was about a 10-15 min cycle to the capitol/mall area.