tl;dr: Stay here. Perfect location, amazing host, and good quality room (esp for the money!)
--
Communication: Excellent and timely. Responsive and incredibly kind. Miguel Angel speaks English and Spanish while his mother speaks only Spanish. I only speak English, but we were able to communicate fine.
Arrival: Easy. Miguel Angel was very accommodating and made arrangements for his mother to greet me. She oriented me to the apartment. The truffle in the room to greet me was a nice touch.
Host: Very friendly, accommodating, and helpful. Responsive to issues and messages quickly and kind. His mom was wonderful and accommodating. Breakfast was great. Issues (light bulb burned out during stay) dealt with immediately. The greatest!
Space: Reasonably-sized room containing a nightstand, bed, and hangers. The bed is warm and relatively comfortable. Bathroom is clean and modern if a bit small. Common room is well-appointed and comfortable. There may be other guests. It was not a major issue for me. Room and apt very clean.
Location: Without question, the best possible location. Right by Plaza Mayor. Easy access to public transit, and many sights and restaurants are close by and walkable.