Diogo is one of the best hosts I've ever stayed with. He cares very much for the feeling of his guests and that everything will work in the best way it possible.
When you are staying in Diogo's apartment, you get a lot more than a place to sleep in - an excellent host, a clean and neat house equipped with everything you need to get a pleasant stay in Madrid, a professional guy (Diogo) who can explain exactly where to go and available for any question or problem. The location of the apartment is great - a minute walk from the Gran Via and the center of the city, close to everything.
Highly recommend!