I had a great Time in Flavia´s Place.
The location was Top. Directly in one of the HotSpots of Lisboa.
Near the trainstation and Metro, perfect to reach. 10mins from the riverside and in view range of castle Sao Jorge.

People with light sleep may have some issues at the weekend with people outside at the street at night.

I just can recommend this place to everybody who want to be inside the city and are not fans of Hotels.