I had a good stay of a few nights at Peralta's apartment. The location is excellent, in the Barrio de las Letras. It turned out not to be the address listed on the airbnb reservation, but it was just down the street so wasn't a problem. You share the apartment with around 4-6 people, with a constant turnover of guests, so it has a kind of hostel-like feel in that regard. Unfortunately there is just one bathroom for everybody to share (and it's not ideal if, like me, you get the room right next to it and hear the whole procession of toilet users). The bedroom doors can be locked, which is good. I found the room itself very nice and the bed large and comfortable. Overall, this was a good choice for a brief stay.