My friend and I were in DC for a short stay and had a good experience with Melis' apartment. My only complaint is that it is listed as a first floor apartment, but is actually a basement (you walk in from the backyard). It is a nice, finished basement apartment, not terribly cold, no mold or anything like that, but it is basically pitch dark during the day which is a little disorienting. Even so, the apartment seemed like a fair value for the price, but I would have liked to have known what to expect.
Melis clearly goes out of her way for her guests, and is very easy to get in touch with should you need anything. She has put together a binder with any information you could need about the apartment and the area, from local food options to info on tourist spots. In the kitchen she had put out complimentary espresso that was quite good, a variety of teas and energy bars. In the bathroom clean towels, shampoo, conditioner, body wash, etc. We didn't have to worry about anything.
Everything was immaculately clean. The friend I was travelling with has bad allergies to dust/mold/animals/etc., but nothing bothered us in the apartment.
The apartment is small, but was fine for our needs--somewhere to put our stuff and rest at night during a fairly short stay. The bed is a pull out couch so I was a little worried it would be uncomfortable, but I slept fine!
The neighbourhood seemed nice, and the location was pretty convenient. We could hop on the (currently free) streetcar a few blocks from the house and be at union station in about 15 minutes. From there we could easily walk to most of the tourist sites, or get transit to anywhere else in the city.
Overall good experience--would recommend!