I spent a whole month in the apartment of Mariano and I had a great time. The place is small but cozy. You can easily stay there with two people for a couple of days, but when you want to stay for a longer period with two people it is perhaps too small.
The apartment is located in the best area of Madrid: very inspiring, lively neigbourhood with a lot of small shops, bars, restaurants etc.
Mariano is a very friendly, easy-to-reach host. Although he was himself not in Madrid during my stay, our communication went well and if anything was wrong, he fixed it immediately. So thank you Mariano for your helpfulness and friendlyness.