The apartment is very nicely appointed. It was comfortable for 2 couples, although you would have to toss a coin to see who would get the smaller bedroom that had no window......but I guess that's ok since you really only sleep at these apartments - right? ,
You can walk to restaurants and some shopping but you need to take a taxi to central Madrid. I would caution though - if you are coming from an international flight and you arrive early in the morning as we did, you typically cannot get keys until about 3pm