Book Maria's apartment, get yourself a Metro pass, and you will have a great stay in Madrid! Maria's place is convenient to the Metro so you can get anywhere relatively quickly in a city the size of Madrid. Maria personally met us to welcome us and show us around the apartment. She had an assortment of coffees and teas, along with croissants, on hand for breakfast. That was a really great touch, especially since we had early flights. It was super clean and perfect for our needs. Maria is quick to communicate, as well, which is always a bonus when you're trying to plan things out.