We stayed at the apartment for 5 days. We were a group of six and the apartment is very spacious, super clean, bright, quite and well located. It's a walking distance from many of Madrid's must see places. The apartment is also located very nearby to many pubs & restaurants.
The host Ernesto, beyond being a really nice guy, was amazing and took care of us from emailing us list of tapas places, leaving food & beverages in the fridge, booking us taxi on our way back and stored our luggage in a near by apartment until our late flight back.
Needless to say, the place is highly recommended.
Way to go Ernesto - it was one of our best vacations.