I cannot recommended Alexandra's place enough!! If you are coming to Madrid for a short break, than you must stay with Alessandra. Her apartment is right in the middle of the city, within very short walking distance of all Madrid's sights.
Alessandra was so warm to me and my girlfriend inviting us in to her home, and her communication throughout the booking was superb (and really helpful).
The room itself is really spacious (with your own private living room), and all amenities you need are provided for.
Again, I can't recommend Alessandra's place enough!