We had a lovely stay in Rex's apartment. We were a group of 9, but the apartment is really big and spacious, so was very comfortable for us all (3 bathrooms was a big plus!) The apartment was clean and well equipped. It's located in a quiet, traditional area with the Basilica and relaxing Jardim de Estrela nearby. Although it's not quite in the centre, it's no more than a leisurely 20-25 walk away or just a short (and cheap) taxi ride away. It's also located on the way to Belem, for those yummy custard tarts. There's a lovely view of the river from the kitchen. It's really close to a supermarket, which was also very useful.
Rex was a good host, communicative and helpful. Check-in and check-out went smoothly. Would definitely recommend this apartment and would happily return!