We stayed in Cristina's apartment for a week. Cristina was really nice and super flexible, we arrived quite late and she waited for us to let us in and gave us recommendations for dinner, etc. She also replied to messages and questions right away.
The apartment is spacious, very clean and right in the middle of the city. Therefore you can easily walk everywhere, but it is also really loud, especially on the weekends, which made sleeping a little hard.
Also, the window in the twin room doesn't lead outside but to a kind of an air shaft, so you do not really get fresh air in this room, which we found a bit discomforting, especially since it got quite warm in the apartment itself. Unfortunately, the WiFi did not work properly, it was really slow and you couldn't really use it.
All in all we still had a nice stay in this big, clean apartment.