I have mixed feelings about this AirBnb. I've stayed in many different locations around the world and there are two types of listings. First there are people renting their own house - fully furnished with 100% of the things you need to stay there a day or a month. The other type are rental only units, sometimes offered by management companies (this unit). This second type of unit are basic with the bare minimum to get by.
Positives: Fantastic location for metro, tourist sites, restaurants, grocery right next door. Good amount of space and floorplan. Natural light. Very fast fiber optic internet.
Negatives: Pictures are better than the actual unit. Unit seems worn down - lots of scrapes/gouges in the walls and floors. Needs to be repainted. Shower is very small. Couch is stained. Has some sort of weird sweet smell (cleaner?) that didn't go away after two weeks with windows open. But the biggest thing that bothered me about this unit was it was just empty. No paper towels/napkins. There was an ironing board but no iron. Salt but no pepper. A washing machine, but no laundry detergent. No cloth towels for the kitchen. No scrub brush or sponge to wash dishes. After complaining to the management company, they were very responsive and provided a few of these things, but only after I'd already gone shopping and bought them all myself.
Overall, if you want a place to sleep for a day or two while checking out the sites in Madrid, its probably great. If you're planning to stay there for any period of time, be prepared to buy everything yourself. I wouldn't stay there again.