We (mi amigo y yo) stayed at Alberto's apartment for three nights, and we can't complain about a single thing. He seems like a kindhearted and very hospitable person who takes good care of his visitors; we were welcomed very friendly & could satisfy a piece of hunger with the snacks that were prepared on the table.
The apartment itself is absolutely clean and comfortable and provides its guests with all the things needed. We didn't use the kitchen though, since there are lots of bars & tapas joints at a few footsteps' distance. Madrid got us hooked and most probably we'll try and get this apartment again when we return there.