First about good things, location is amazing. Very quiet street in the heart of Madrid, minutes away from bunch of cafes, restaurants and clubs. 5 minutes walk to the main square (Puerta Del Sol), literally in front of the house is metro station.
Apartment was clean, but none of the bedrooms had any windows and were really small. We didn't see this when we booked the place.
Toilets are nice and probably recently renovated.
No elevator in building, apartment is on second floor.
Our main problem was check-in, like many times before and I hope airbnb hosts will one day realize how annoying this is, we were greeted by cleaning staff who didn't speak a word of English. Furthermore they were just starting to clean the space when we arrived around 3 pm.
If you don't mind small bedrooms without any windows and not completely furnished this is an excellent place for stay mainly because of it's location.