The flat is very well located in the Lisbonne historic center. You are very close from small shops and bakeries to prepare your breakfast just few meters away. Even a chinese restaurant for inexpensive meals.
The flat is as described, and you fell comfortable in the main room and living room. We didn't use the small room.
The street could be somehow noisy in the night but as long as you know it and you have long walking days through Lisbon, it can be easily managed.
My summary: the location of this flat makes it exceptional.