My partner and I stayed in Guillermo's flat in June 2017. The apartment was cool, clean, and the perfect size for us. It is less than five minutes walk to three Metro stations, but also within walking distance of most of the spots we wanted to visit. Malasaña was the perfect place for us to stay - so central but incredibly laid back and peaceful, with great art, bars (especially craft beer!) and shops.
Guillermo was very quick to contact us, and sent us all of the relevant information. Antonio, who met us on arrival, was incredibly welcoming and gave us an informative tour of the flat, and was on hand if we had any questions during our stay. We had use of clean towels, television, wifi, hairdryer, iron, cooking utensils, fridge/freezer, washing machine, as well as bathroom products and great coffee!
We loved our stay in Guillermo's flat, and when we return to Madrid we definitely hope to stay here again!