I stayed this place with my wife and parents. Mafalda&Claudia were very helpful! They kindly supplied us how to get to their the meeting point which is near the apartment and explained us the area. We went to their recommended restaurants and they were absolutely great!
Area is right in the middle of the old town and as everyone comment on here, you will have many stairs to go through but its part of the Porto experiment. As you can see, Luis I Bridge is right next to it but you don't get disturb by the train noise. Absolutely fantastic view!!
I will definitely stay again when I come to Porto with group of people. Great place, great value.