Nice place, but there is still room for improvement.

Pros: Privacy; you have the whole place for yourself. The location is good; close to the Cais do Sodré station, close to attractions, and lots of options for coffee or food. Friendly host, he helped me with my luggage during check-in.
Cons: Safety; locking system was poor, the window lock was not working. One day during my stay the host wanted to come pick up some clothes which made me change my plans. The neighborhood was a bit sketchy at night. The bedding could be more clean, one night I woke up due to bedbug bites.

Before you book you should consider: the building is old - noticeable cracks on the walls, no elevator, internet is a TP-link device - you have to hold it close to the window, the neighborhood gets noisy till 2am, no good noise insulation, the room is private yet the apt entrance is shared and the key for the room is not working properly so there is an extra quite uncomfortable locking system (security roller).