We had a great stay at Fontainhas residence. Communication with Gonçalo and his team was excellent and they made sure to meet us upon arrival to talk about the city and give us recommendations. The apartment is well equipped and location is great, walking distance to many touristic attractions, to the metro and restaurants, cafes and supermarkets. The view from the balcony is incredible!
Size is perfect for 2 people, but could accommodate 4 people without being too cramped.
The only issue we had during our stay was with noise coming from the smoke alarm, which was taken care of by the host, and coming from the bar located next door, but that was only in the first night. However, if you are a light sleeper I would recommend bringing some ear plugs.
Overall, we had a wonderful time in Porto and would stay there again.