The apartment was as advertised. The kids loved it because its kind of kids sized. My wife and I hit our heads on the ceiling a few times, but still enjoyed it. The apartment is right next to the rooftop terrace, which we used a lot in our short time there.
The water kind of makes a sour smell in the apartment and the AC is a bit old, but that's probably true of most Madrid apartments.
The host let us check out late because we were delayed in the morning. Overall I am very happy with our choice to stay there and would come back.