Paula's place is sparkling clean and in one of the greatest locations in Madrid. It's easy to reach with public transportation, there are several supermarkets around and plenty variety of restaurants and cafeterias. The access to the terrace on the top is also great!
However, the stairs to the apartments are really small and slippery so elders or people with walking disabilities should be very careful. For light sleepers like me: the walls are thin and one can hear everything from adjacent apartments.
There are only some minor improvements that could be made, like having napkins in the apartment and a pen to fill out the form, as I never carry one :P
Nonetheless, the experience was great and I would definitely recommend and repeat!