The apartment is really small, but is located in an ideal place to explore Madrid and the owner did everything possible to make the guests comfortable. We met with Alberto only once when checking in but every day we saw evidence of his concern for us - a list of museums with opening hours, a list of restaurants, city descriptions, necessary household and sanitary trifles, and so on.
Alberto, thanks a lot. Madrid is a magnificent city and we hope we will return more than once.
As for the apartment rating itself - my rating is 4 of 5 due to the narrow steep wooden staircase to the entrance of the apartment on the rather high first floor. Could make a problem for some people.
Vladimir