Walls are paper thin. You can hear everything the neighbors do. The whole building is for short time rental apartments, many many people coming and going all the time, very noisy. All the units in the property are airbnbs. So you can feel guilty renting this place and contributing to push real people from Madrid out of the neighborhood. But let's go back to the apartment... two small towels that are not great. Mattress is uncomfortable. Wifi did not work properly. Signal was very weak. I stopped trying the wifi after the second night. There's a construction going on across the street. It can get pretty loud during the day.
Location is great though.