This review is more for Rodrigo and his mother (whom I give 5 stars), than the apartment (hence -1 star).
I chose this apartment because of the location (which is great), cleanliness, proximity to a 24-hr market, train station, and metro.
And, most importantly, because the description said it was a quiet apartment and the community observed "quiet hours from 11PM to 8AM".
Unfortunately, during our stay the neighbors and their children made a lot of noise until 3AM, which lead to several nights of not sleeping well. Overall the walls are thin, so we could hear the neighbors conversation word for word from our bedroom. But it was the children laughing, shrieking, and crying at 3AM we could not tolerate.
When I told Rodrigo, he talked to the neighbors about it, but it was not a factor he could control. Ultimately he let us move into a different apartment in the same neighborhood which was much quieter, to resolve the issue.
I commend Rodrigo and his mother for their help and advice while staying in Madrid, and how they handled the situation. They even helped shift all of our belonging into the other apartment. I recommend booking with them based on their hospitality, receptiveness, and their desire to provide their guests with a positive experience. They have several apartments in Madrid, so I recommend contacting them before booking to find one that is right for your needs.
Overall, if you are a heavy sleeper, or don't intend to be home very much at night, or don't mind noise, this apartment could work for you.