The apartment is in excellent location, right in the middle of the city centre, yet it is very quiet and cool, very nice peaceful place to come back to after a whole day of sightseeing etc. Also, the apartment is spotless, very clean!
Manuel is very professional, he is very helpful, you do not need to do any preparation in terms of what to see and do in Porto as Manuel will explain the city and give tips better than any guide book. Please if you love food ask Manuel about good places to eat as he suggested to me few restaurants and I visited them and I had fabulous meal. Very affordable too. If you love fish, please ask about the place where they grill fresh fish for you, I visited it twice and could not get enough of it. It is a bit further out, but very straightforward to get to, and you get to see the city as well if you go there by bus 502. It is not far from the apartment and goes to Matosinhos Mercado directly. Also, please visit Santini ice cream parlour if you love ice cream. Excellent!
Overall, I will come back to Porto and Manuel's apartment is perfect to stay in.