Paulo Eduardo was really helpful, giving us precise instructions on how to reach the flat from the airport. Mr Sergio and his wife did the rest, nicely welcoming us on site, smiling and being truly kind when we needed some help.
The apartment is exactly like shown in the pictures, in the middle of the Barrio Alto area and at walking distance to all the interesting spots in old Lisbon, which makes it a perfect location to start exploring the city. It comfortably fits up to 6 people. Plus, from the tiny balcony you'd have a view over the roofs, towards the river. Everything was clean and the hot water worked fine, as well as the air-conditioning (but we opted for leaving our windows open at night, letting the beautiful Portuguese sun in).
There are many cheap bars and some good restaurant around, so even if you are not keen to walk much at night, you still have plenty of choice: as a group of friends in our late 20s, we couldn't ask for more!