Bea and David have foot for foot the most well appointed Airbnb I have ever been in. It's a small space, maybe 300 square feet, but it has a stylish bathroom with a high-tech shower, a full kitchen, a drop down kitchen table, a washer and TV with Netflix. That said, it's a squeeze for two people, certainly impossible for more, and it's in a basement with no outdoor light. It has a window with electric lighting that simulates outdoor light, and my wife and I didn't mind too much, but some people might.
Maybe the apartment's best feature is its location. It's in one of Madrid's hippest, most fun neighborhoods, and it also has good access to most neighborhoods tourists will want to visit. Bea and David were also great hosts. we didn't get a chance to meet them but they were very responsive, offered great recs, and checked in regularly to make sure everything was going well.