Great place for a traveling couple. The apartment is on the smaller side, but this should be no problem if you are planning on spending most of the day exploring Madrid. It is a nice and cozy apartment that is well decorated. The location is 10/10, super close to multiple metro stops, attractions, and good food. We used the metro very little times because everything is walking distance.
As other guests have noted, the area is busy late at night which makes the apartment noisy. It should be no problem if you have ear plugs, but expect to hear it if you are a light sleeper. The good thing about this is that the area feels very safe to walk around late night.
Marta met us upon arrival and was great help when asking for tips and recommendations. We had a great time in Madrid!