David's place is very comfortable, inviting, and very very close to more bars, coffee shops, and restaurants than you could ask for. There's a Trader Joes and a RiteAid less than a minute walk away. All the museums and stuff were about a 10 minute Uber ride away. We didn't use the Metro, but it's an easy half block walk.
Despite the convenience, it was pretty quiet and felt very very safe. As a female, I would not have thought twice about staying here by myself. We heard people walking by the house every so often (It is a garden apartment) but that's just part of being in the city. Knowing how close it is to such a lively area, I would have expected FAR MORE noise. The bed is super comfortable as is the couch (my husband and I pulled it out into a bed, grabbed an extra comforter, and lounged in the evenings). There were lots of little toiletries if you happen to forget anything. We didn't do any cooking, but the kitchen is stocked and ready for any cooking you might want to do. Our flight arrived in DC at 11 and David was gracious enough to allow us to drop our luggage at the house while he was cleaning. That was a total lifesaver so that we didn't have to limit our afternoon's activities to whatever we could do while dragging a week's worth of our stuff around.
My only complaint was that the hot water is a little bit limited, so unless you are super duper fast, you'll have to stagger your showers if you have multiple people staying. It was enough to get through a "normal" shower, but I wouldn't linger for too long.
Overall, the experience was great. I would definitely stay here again.