The apartment is very nice, spacious and suitable for large groups. We were 15 people and each one had his own comfortable bed, even though the apartment has only 7 rooms. The house was clean and decorated in a quite neutral way, the kitchen was convenient and well equipped. It is located in the center of the city and offers a beautiful view over it.
One should note that noises from the street can be heard in the apartment, we didn't have an issue with that as nothing was too loud. Also the leather of the couch in the living room is quite damaged and could be replaced.
Even though we didn't meet João in person, he was rapidly responding to emails and was very helpful. All in all we were very pleased with our choice and would recommend it.