I stayed in Joao's place for 5 nights with 5 friends. The apartment is located in the centre of Porto and everything is walkable, which we liked very much! From the airport we took the metro to the city centre (Trindade) and from there it was a 10 minute walk to the apartment. The place has two showers, which was very nice since we were staying with 6 people. However, keep in mind that the showers do not stay hot for 6 shower turns of 5 minutes. The beds were okay, one of them creaks very much, which cost me quite some sleeping time.
After all, I would recommend this place because I think the value for money and the location are great.