This is an amazing location and a pretty good bargain, especially if you want to be near the Mall, Congress, The Supreme Court, etc. and a metro. The Metro is steps away, (and even if you don't want the Metro, there are usually cabs at the Capitol Hill Club) and even in March the Mall is walking distance away.
The place itself is great. Awesome TV set-up in a large living room perfect for however many people you have staying there. The main bedroom is quite large, and the second bedroom, while a little smaller, is perfect for a kid or two. I would say there is plenty of room for the four people (not including infants) that are allowed here.
The couch in the main room is great to spread out on and watch TV while visiting with people at the dining table, the kitchen is large enough to provide food for a short-term visit, and the appliances are appropriate for even a longer duration stay.
Host was very responsive, often within minutes. We didn't have a car, and I would say if you are renting this place you don't need a car because transit is so close and easy.
I got back to DC a few times a year now, and hope to be able to stay here in the future.