We had a wonderful time! Porto is beautiful and Carlos' apartment is in a really convenient location: the metro is just a few minutes away so it is perfect for coming and going to the airport with luggage, and the city centre is just a ten minutes walk away! We usually got out in the morning and stayed all they outside visiting the city, so the place really suited us.
The apartment also has a few supermarkets nearby and a really nice and well supplied kitchen if you want to eat inside!
The place is clean, quiet and in a building that looks like it's been renewed recently; when we arrived we've been welcomed by a friend of Carlos who gave us directions for the city and was extremely nice and helpful
We reccommend the place, a really good experience!