My college-age son and I stayed here for three nights. We were there on a short father-son sightseeing trip. Dan's description of the place on Airbnb site accurately describes the place, so I'll add just a few details.
Location--Perfect for us. DC has a rich history of row houses, and we enjoyed getting to experience this residential setting. Quiet spot nestled in a neighborhood yet close to public transportation and shops/restaurants.
Accommodations--Not much to add to the website description and pictures. Everything was charming, clean, and inviting. What the pics do not convey was how spacious the front bedroom (where we slept) was. It was great having plenty of room to spread out. We didn't even get to take advantage of all that Dan and Chingchai had to offer. Our visit was too short to need to use the kitchen or laundry facilities, but it was nice that they were available.
Hosts--It's rare, in my experience of staying at many different places over the past fifty years, to find a host who can find the balance between giving guests all the privacy they want and providing those guests gracious and personal hospitality. Dan and Chingchai are masterful hosts. On our first night we arrived quite late and needed to sleep in. The next day we were exhausted from our activities and just wanted to be alone. Our hosts let us have all that time to ourselves. However, on the next day, we eagerly accepted their invitation to join them for after-dinner drinks. We had a wonderful evening visiting with Dan and Chingchai. The next morning's conversation at the kitchen table over a farewell shot of espresso was a great sendoff. I can't say enough about the quality of our hosts.
Extras--This is a place I would recommend to almost anyone. There are only a couple of exceptions, which Dan more or less covered in his description. If you plan on driving around in DC, this is not for you. Too difficult to find parking. Public transportation is close, and we used it during our stay. The train lines are a bit of a walk, but the bus stops do the trick.
The only other slight caveat is that the house is in a somewhat hilly area. In some of our comings and goings, we had some fairly steep sidewalks to climb. It wasn't at all a problem for us, but it could be a difficulty for people who get easily fatigued due to health problems or old age.