I can't stress enough how much we loved this apartment. Nestled in Malasaña, you get all the neighborhood's night time vibe, yet the apartment's location within the building makes it quiet and pretty much soundproof.
Its accessibility to most places one wants to go is not more than a 20 minutes walk (many of them are a 5-10 mins walk, so if you stay within Centro, you won't need the metro at all. We prefer to walk everywhere, anyway). The only time we took the metro was to go to Puerta de Atocha to catch a train, and considering that we only stayed 8 days, most of the places and neighborhoods we wanted to visit are close to the apartment.
Diego keeps this spacious apt. clean and neat. The photos displayed are exactly what you see/get, including the upstairs terrace (perfect for a morning coffee and smoke). As a proper host, Diego stays in touch every so often to make sure you are comfortable and to provide anything you might need, which is a nice touch.
We liked the convenience of the supermarket across the street and the organic mini market 2 minutes down the street.
Next time we go back, we'll surely stay at Diego's, schedule permitting.