The apartment has an excellent location. We wanted to stay in Malasaña and that's where we spent most of our trip, so Fermín's place was ideal for that. It is in walking distance to all the lovely central areas. We walked to Prado and Retiro and the Salamanca area is at around 25 mins by walking.
The apartment is clean and has everything you need. If you travel in winter, be aware though that the Malasaña area has old buildings where the heating is mostly electric, so it takes a little while to heat the apartment after hours of being away.
Fermín is a very nice host, he made sure we have everything we need, he's super easy to contact. We had a great holiday at his apartment!