It was great! The apartment is perfect not only because it is really nice but also due to its incredible location, just aside the river near the center of the city. In addition, Cristina met us at the apartment and helped us a lot, explaining in detail many good places to visit.
It was my first experience in Airbnb and it actually shifted my expectations. If I go to Porto in the future I will try to stay again in Cristina's apartment without any doubt.