I stayed 6 days in the flat. It's very well equiped and was super clean, wifi is perfect.
Very close to subway, easy to go to city center (you can even walk if you feel like it) and the neighbourhood has everything you need.
Joao has been a very nice and helpful host, always available to answer any question I had. Thank you.
My only remark is that if you are sensitive to noise, being on the ground floor has some disadvantages, nevertheless nights are very quiet. You might also notice some planes arriving or leaving as Porto airport is close to the city.