Great apartment. It's spacious, has a nice bed, good shower, aircon, enough space to store clothes. Location is close to a metro station, which brings you into the city center within 15-20 minutes.
The area surrounding the apartment is safe and quiet. As is the building itself. The apartment is on a floor with 7 others that are rented through Airbnb, but I never heard any other guests after 22:00.
Really good place to stay to explore Lisbon.