The flat has everything that you need for a few days break including the perfect location to explore Madrid as everything is within walking distance. The area can be a bit intimidating, but as long as you are following basic safety rules, you are fine. Check-in system with the keys available in the building is a great feature especially when you are arriving late. Everything was very clean and the patio area is definitely an added bonus to enjoy the sun with the morning coffee. There is no kettle in the apartment, but we simply boiled the water in the pan for tea and there is a coffee machine.
Very quiet street, so definitely great location for a good night's sleep without noise nuisance.