I stayed two weeks in the lovely apartment of Catarina and Rui while being on a business trip in Oeiras. The place is in a perfect location, 9 minutes to the train station, 3 minutes to the next supermarket and lots of small eateries and nice restaurants around. Also the area is super safe and walking alone outside is possible during all times.
The apartment is perfectly clean and has everything you need both just for a night or for 2 full weeks of cooking, washing and working like I did.
Highly recommended and the best AirBnB experience I ever had in Portugal so far.