The apartment is ideal for exploring Lisbon. It has everything you need for a comfortable stay and is in walking distance to everything.
The neighborhood is quiet. The apartment is above a café though, where we experienced quite a bit of noise from, but only during the afternoon hours when we were in the apartment before going out to dinner at night. During the night the neighborhood is nice and quiet and we slept very well.
The interior is personalized (not all from IKEA as it is in many apartments through AirBnB) which we found charming and made it feel like a home away from home for us.
We would definitely recommend Mafalda's apartment to our friends who are travelling to Lisbon.