We really enjoyed our stay at Goncalo & Miku's. This Airbnb is in a great location, close to the water and in walking distance of the Castelo, the busier area of Bairro Alto, and many viewpoints. The house was large, clean, and comfortable and check-in and check-out were easy as the hosts were very friendly and responsive.
However, be aware that this is the oldest part of the city and is very hilly with maze-like streets so Maps is a must in getting around (although this only adds to the appeal in my opinion). The Airbnb is also not really accessible by car, and on the second floor so I wouldn't bring large suitcases as you will have to carry them up several flights of stairs to get to the Airbnb.
Overall, we had a great stay and I would definitely recommend this Airbnb.