Mariano's place looked exactly like in the pictures, unique, artistic and spotless. Its location extremely convenient, right in the center of Madrid, we did not have to take the metro once during the whole weekend we spent there (it's good to know though that there are two metro stations pretty close).
Mariano himself is very helpful and friendly, making our staying there all the more easier.
Definitely recommended, if I am ever in Madrid I hope Mariano's place will be available!