This is my sixth time in Madrid and I can say without reservation that Alex's beautiful house offers the best value for money among all the properties I have stayed at.
Firstly, to say it is literally impossible to find a better location in Madrid. The neighborhood is semi-pedestrianized, lively yet quiet at night. At a walking distance from practically everything you want to see in Madrid - in one of Madrid's most emblematic historic neighborhoods.
The pictures don't do justice to the apartment which is far more spacious than anything you will find in this area. It has practically everything you need for a short or long term stay in Madrid. A newly renovated kitchen, two really good bathrooms (with a spacious massage-shower thing and one of them even has a hot-tub Jacuzzi!
What my wife loved the most was the walk-in closet which meant where we could dump all of our stuff and leave the rest of the flat totally free. The living room is spacious and has a balcony facing the street in which Miguel de Cervantes is buried.
Alex was charming, checking up on us periodically and even brought a blender for cooking when we asked for one. Oh and a cleaning service is also available in the block for a reasonable hourly rate.
The only feedback I would give on this flat is that it perhaps needs a larger TV (and cable for non-Spanish speakers) and a shorter password for WiFi!
Everything else was literally perfect and I have found my ideal home for my next stay in Madrid.