Keith and Yoshiko's basement apartment is in prime location. Their house is located walking distance from public transit and about a 25 minute walk to the attractions and the national mall. It is also nearby a ton of local restaurants that are opened pretty late. The neighborhood has culture and is safe. There are also lots of uber drivers nearby for about the same price of public transit for two people.
The apartment itself is super cleanly and spacious. Keith and Yoshiko provide you with everything that you need. There are useful maps on the wall and personal care items such as toothbrushes and toothpaste, lint remover brush, shampoo/conditioner and body wash, etc. There is a fridge (with bottles of water), iron, coffee maker, and television. The bed is large and very comfortable.
Keith and Yoshiko gave us total privacy while still ensuring that they were fully available and accessible. The basement has two private entrances so you won't intrude in their space as well. The hosts were extremely friendly and accommodating. They allowed us to park in their driveway and even provided us with refreshments for our trip back home.
The one and only downside is that there was construction going on behind the house so it got a little noisy around 9:00am. But other than that we would definitely stay here on our next trip to D.C.