Alberto's place is lovely. Small but perfectly formed for a short stay visiting Madrid. We spent 2 nights there. Check in was easy and we were given good tips about the town too which is also helpful. The only reason why I am not giving it a 5 star review is because the toilet chain was badly repaired and broke the day we arrived, and the shower doesn't drain very well so it easily floods the bathroom.
The apartment location is brilliant, the area is lovely and easy to walk to most places, the metro is also a short walk away.