We had a great time at Alfonso and Guillermo's apartment.
The experience is very unique, it made me feel like a local instantly. Try opening the bed-size couch, and the windows, and enjoy a siesta while listening to the neighborhood sounds. Then have a coffee in their patio to get back to life.
The location is definitely a highlight. Subway stations are really close, yet walking you can get everywhere. The police station is right next to the apartment, which I guess is convenient. More convenient though, the bakery on the other side. Try Grace's "tortilla de patatas" to taste Spain.
Thank you Alfonso & Guillermo!