Carmen and her son are super welcoming, I had a delay in my flight and her son stayed up until I arrived (~1 am). I met Carmen the day after that and she was very kind and helpful. He location is awesome, 5 min walk to Atocha station and 10 min in metro or 'cercanias' from the center of Madrid. The room was very comfortable and clean. They have two pretty cats at home but it's still clean. I had any problems at all and I hardly recommend Carmen.