The apartment is absolutely perfect. The location, more specifically the street is not so great, but it's close to all major points of the city. The street looks a little sketchy at night. Try to ask as many questions as you can to the wonderful hosts, Marta and Adolfo. You will not get a lot of useful information by asking people on the street or at shops. People are not the friendliest in Madrid. They are lucky to have a beautiful city. Oh! Be very specific of the arrival time to make sure you don't have to wait until the apartment gets ready.