We spent two months in the apartment working remotely. For two to three persons, the apartment is perfect. It is located close to Chiado and Bairro Alto. There are bus, tram and train stations nearby. From the train station you can visit lots of beaches and Cascais. The first beach is only a ten minute train ride. The apartment is fully equipped, also for longer stays (washing machine, dish washer, vac cleaner, ...). Internet is great. We had parallel video calls while youtube streaming without any problems and we never had a down time whatsoever (10/10). You can hear people outside on the weekends in the evening (but thats probably the case everywhere in the center...). The view is fantastic. Communication with Pedro was super fast, easy and friendly.
tl;dr: fantastic apartment, we would come again any time.