We stayed for one night before our flight out of Lisbon. The location is about 10 minutes walking distance from the closest train station and 8 minutes from the closest subway.
The public hallway outside is pretty grungy but the unit itself was clean. The living room smelled lightly of cigarette smoke, but unclear if it was the room itself or from outside.
Overall, for our purposes of being close to the airport, was a good option!