I loved Maria's flat, I highly recommend it to anyone staying in Lisbon! The flat has an amazing location, it's literally 2 mins from the metro / train station and the tram, some shops and 5 mins from the main sightseeing places.
The flat is lovely, very convinient and has everything needed even during a longer stay (iron, hair dryer, washing machine, etc).
Communication was very easy, Maria's team is very flexible, even I've got all the information needed about the city and the locals.
Many thanks for everything Guys, I'll be back!!!