The apartment is wonderful, better than I expected! Not only beautiful, but also very functional, with lots of drawers to tuck your stuff in. If you, like me, are wondering if the apartment has a wardrobe (because it is nowhere to be seen in the photos) the answer is "yes", it is in the bedroom. There also is a shoe closet in the entrance hall . The bed is very comfortable, linen are of high quality and the kitchen is also very well equipped, although I only had breakfast and did not cook.
I visited in October and the weather was very good, so the a/c was enough to heat the room. Maybe in the winter an extra heater will be needed, since the apartment is in a high ceiling building.
The bathroom is heated by an electric towel hanger, which I think will be ok, even in colder weather.
The location is superb, right at the beginning of the pedestrian part of busy Santa Catarina street, so a taxi/ car can stop almost outside the building, while you are still staying at the most vibrant part of the city. All stores are literally at your feet and everything is within walking distance.
The communication with Porto City Hosts was very good, they responded to all my emails and requests rightaway.
All in all, a most enjoyable stay!