As newcomers to Madrid, we were not sure what to expect, but we were delighted with the city and thrilled with the location. The extremely narrow street prevented much car traffic, and the residential street precluded a lot of celebratory noise from reaching us.
The property itself was clean. The bathroom was easy to use and didn't leak (!). All the plumbing was fine. We didn't spend a whole lot of time in the apartment, but the air conditioners in each room made it extremely comfortable for sleeping.
Right around the corner is a delicious breakfast shop that makes great coffee. We found the service friendly, too.
Our check-in process was a little difficult because Marta checked us in, and she spoke no English at all. We did fine, though, with some help from the SpanishDict app.
At the time of our visit, there was construction going on outside, but only during the day, and we were not inclined to nap on vacation. But on the opposite end, we were treated to a neighbor's opera singing lessons across the hall every morning, and that was lovely! (We later heard the same woman singing at a music academy through a window.)
The subway is literally a block away and very easy to use.
All in all, a perfect vacation.