It was really nice, exactly as on the pictures. Very friendly hosts, they even gave us a map of Porto and gave us some guidance.
We came pretty late and there was no problem at all, as well as it wasn't with the check out. And they were also available on the airbnb during our stay.
The place was welcoming and clean. The location of the flat is superb, you couldn't ask for better. It was in the historical center, everything walkable and 2 minutes walk from the train station.