The apartment is really lovely, very new and modern. We had a very pleasant stay! The area in which the apartment is located is fine. There are some cute restaurants nearby (try out Bloom and Come Prima!!) and the train station and port are within walking distance. If you go to Lisbon, definitely take a train and go to Cascais for the day!
Some things to take in consideration before booking: the apartment is quite noisy en gets hot really quickly, even when you have the airconditioning on every now and then.
Overall this apartment is really lovely and the host is great! Gives some great tips for things to do/see in the area and answers your questions very quick. We definitely wanna go back sometime!