Had a great stay at Will's place. The place was clean and pretty spacious. Bathroom and kitchen were also clean. Airconditioning, wifi and the electroninc door lock all work perfectly.
The appartement is serviced by two nearby metro stations as well as several bus stops. A cab from National Mall to the appartment is also 'only' ten bucks and pretty fast. Alternatively, a twenty minute walk will get you to the National Mall.
Area is pretty gentrified. I was traveling alone and never felt unsafe at night. I saw some earlier reviews talking about stripclubs, it appears said clubs have now been made into church community centers. Make of that what you will. Neighborhood is pretty hip and there are plenty of bars and trendy stores nearby.
Will responded quickly when I had questions, and was quick to provide extra bathroom towels when I needed them.
Only minor '(potentially) negative' point is that you need to realize that you're sharing the apartment with others. I personally had a great time with the other people in the appartment, but expect that you have to communicate clearly about things like light, music and airconditioning. Especially late in the evening/at night. Also keep in mind that there is only one bathroom, so you might have to wait a while until your turn.
Overall had a great stay and can would definitely stay at Wills place again!