The apartment was super clean and the location is great! It's in walking distance to almost all of Porto's highlights. André is a nice host, he even gave me the code for the apartment two hours before the normal check in time so we could leave the luggage there. There were only two small inconveniences: the apartment gets cold during the night (for February, I'm sure in the summer it's fine), and the floor is also cold. Bring some slippers if you plan to stay here in the cold season. And the second was the internet - it's kind of slow and the latest MacBooks can't connect to the network due to weak security. But I'm sure this will be fixed as it's just a router setting that needs to be changed.
All in all, if you look for a great value apartment close to everything, search no more.