I rented a room at Julio´s apartment for a night while connecting flights in Madrid. Location is great, a couple of blocks away from El Retiro park, a lot of restaurants nearby. I didn´t meet Julio, since he was on holidays, but he was very responsive and always in contact, so I could have a smooth arrival, as it happened. I stayed at the apartment only for about 12 hours, but as far as I can tell from my experience, I would recommend staying at Julio´s apartment.