Location is the winner here. Close to Alonso Martinez metro stop (3 metro lines intersect here). Close to great coffee shops (Natif and Osum), healthy food (Honest Greens, Cocohouse, etc.), and dozens of other eating/drinking establishments. Walking distance to the hippie bylanes of Malasaña, shopping district on Gran Via, etc.
About the apartment itself:
Positives: beds are comfortable, washer works, there is a drying rack, kitchen is basic (but adequate), having two toilets helps in case you are a family of four, automated check-in-check-out system is great, TV is helpful, host is available on WhatsApp any time.
Negatives: Lack of natural sunlight, patchy WiFi, lack of 4/5G signal inside the apartment.
Overall - I would stay here again.