We had a fabulous stay at Rick & Amy's place in the Logan Circle neighborhood. The location can't be beat if you want to enjoy all the excellent restaurants and bars in the area, and it's an easy ride on the metro or bus to see the sights. The apartment itself is very clean and comfortable, and the hosts are very communicative and helpful.
One thing visitors should know is that the entryway is very cramped and awkward and so this is probably not a good choice for someone with mobility issues. For most people this won't be a problem and didn't detract at all from our stay.