The apartment is right across from the train station, but is surprising quiet at night with the windows closed. We had no problem sleeping. The blackout shades on the windows were amazing for keeping the light out in the morning.
The location of the apartment is great. We walked everywhere. Ricardo was responsive before the trip and during our stay. As stated, there is no lift. So, if that is a problem, this would not be the place for you. Also, the floor boards in the bedroom squeak, so if you get up in the middle of the night to use the bathroom, your partner will certainly hear the squeaking.
Overall a great place to stay while in Porto.