We had a great stay at Susana's place. Susana welcomed us very warmly and provided lots of information as to where to go, what to see, where to eat. The apartment is located in a very lively neighborhood and you really get to know the spanish livestyle while staying here. We didn't have to use the metro once as all the sights are easily reachable by foot. The only minus (but that's not Susana's fault): in Madrid the garbage is collected in the middle of the night, so make sure to bring ear plugs!