Diana was a very responsive host and as my flight arrived 7 hours before check-in, she suggested the perfect way to spend my first morning in Madrid, luggage free. Unfortunately I arrived late at check-in time, missing her by 10 minutes, but she arranged for a friend to check me in an hour later, and her kind friend helped me lift my luggage up the five flights to her studio.
The stairs were a surprise, as was the little low-ceiling hallway to the studio, but everything else was exactly as seen in her listing. It is a lovely studio and very comfortable, bed, shower, portable heater and all details. Diana had graciously made a reservation that night for a fabulous flamenco show that I had trouble reserving from the USA.

The only downside I experienced was:
Navigating the stairs solo upon leaving with heavy luggage, noise from neighbor through thin wall, shower handle temperature control was sticky.

All in all I highly recommend Diana, her studio and the location in Malasaña next to the metro station. Just be prepared for stairs and bring some ear plugs if you're a light sleeper perhaps?