We had a great stay in Ruben's apartment. He is a fantastic host. Not only did he respond super fast to any question we had before arriving, he checked in with us during our stay, asking how we were going and if we needed anything, without being intrusive at all. He is also super thoughtful in how he has equipped the apartment eg down to a shopping bag so you don't have to buy the plastic ones.
The apartment is in a fantastic location, very very central, walking distance between the Prado and Palacio Real. Great amount of space. Everything is clean and everything works. It is decorated in a a style like the host - friendly enthusiastic creative and cheerful, with a great atmosphere. Small Supermarket around the corner and larger one down the street 2 mins. Lift in the building. Plenty of places to eat out if you want. Even though it's a busy area it wasn't noisy at night. Overall highly recommended.
Ruben and his place made our first visit to Spain and Madrid super easy - we felt like locals even though we didn't speak Spanish, and we would go back in a flash. Thanks Ruben.