Stayed for a week and enjoyed the place. It is quiet, clean, equipped with all necessary facilities, I have not missed anything. The apartment is in a historical district, within walking distance to main attractions, supermarket and metro station. There are plenty of bars and restaurants around.
Quentin is a great host, he will make sure you feel comfortable and your stay is free of troubles, and he will not bother you during your stay.
I truly recommend this place and it will be the first one to check availability during my next visit in Lisbon.