Beautiful apartment! It was perfect for our group of four for a one night stay. You cannot beat the view of the plaza mayor, and the AC worked wonderfully during the brutal Madrid summer heat. Communication with the host and co-hosts was phenomenal. Jonas was prompt to greet us at the front door and show us around the apartment. I was surprised about how little you actually heard from the noisy plaza once the doors were shut.
Only thing to note: if you are a taller person (as I am) the upstairs ceiling is very low (obviously, it’s an old building). For one night, I could deal, but for a longer stay this may be bothersome. Of course, you could always just stay downstairs!