Mario's apartment was well appointed and modern, close to the Trinidade metro station and within 10 minutes walking distance to all of the sights of Porto. There was even a free breakfast included! Mario was very easy to get in contact with and the check-in process was quick and efficient. He even created his own app with an illustrated guide to Porto. Would definitely recommend especially if you plan to travel to the Douro Valley or other sites during tour stay given the close proximity of the metro to get to the train station.