We had a lovely stay in Madrid. Anas apartment is perfect if you're staying for 3-4 days in the city. Almost everything is within a walking distance - we never took the metro and it's also only 10 minutes away from Puerta de Atocha train station. The barrio is quite lively and alternative with lots of bars and restaurants. The only disadvantage is the small size of the apartment and the noisy neighbors (but that was probably just bad luck). But it's defo enough for two people. Ana and Juan were really helpful and kind and we can only recommend staying in their apartment.