My friend and I have spent a couple of days at Mario's place in Porto and it was a great experience overall. Mario is a great host and did his best to make us feel like home, despite that we met him only once before our leaving. Mario is very sociable person, who takes care of his guest: he borrowed us a couple of umbrellas and left us a nice map prepared by him to explore the city! This was really nice of him and very helpful as there were some very good recommendations to be taken. The flat itself is really clean and bright as in the pictures and located in a good district so all the main attraction points may be reach while walking on foot. To sum up it is really nice experience and Mario apartament is recommended to be chosen as good place to stay in Porto.