Fantastic location, great communication with host and smooth check-in/-out. Everything was as stated in the listing. It is perfect for a short stay. For a longer stay, as it was quite expensive, I'll be a bit fussy: the furniture was hit-or-miss: beautiful antique furniture mixed with an uncomfortable sofa and wobbly dinner table (I used it as a writing desk so the wobbling was quite distracting) and cheap, noisy modern flooring. Wifi was sometimes weak.
Don't let that put you off if you mostly want this place for the location though. For that, it's practically unbeatable, literally a minute's walk to Puerta del Sol. You'll stay for hours watching the people walk by from the balcony or winter garden!