We enjoyed our stay at Diogo&Filipa's place.
The Flat is located at a quiet street very close to the end station of the blue metro line which makes it easy to get to the city center. Communication with the owners was fast and easy, the flat was clean and check-in was uncomplicated.
Note: It is an old building, so naturally it is not that well sound isolated and some installations have seen better days.
Overall its a nice apartement for a short trip to lisbon!