Nice and cosy apartment. It's brand new and you can really see it. The decoration is really nice so it feels a little bit like home. Everything that you need is provided (enough dishes, toaster, kettle, french press for coffee, sponge, soap, ...).
The location is the best part of this apartment. We really liked the neighborhood. There are plenty of bars and restaurants.
It's also quite well centered so you can do most of the visits by walking. It's also really easy to come from the airport.
The only issue was the noise coming from the hall through the door. We can hear when people open their doors for example or speak in the hall. If they can fix this part, it's really the perfect place to stay in Madrid.