Highly recommended! The location is interesting, overlooking the lively Rua das Flores, in the historical district. It's also practical, as there's a small market (Minipreço) just around the corner and numerous restaurants and pastry shops within easy walking distance. The main attraction I specifically wanted to visit was the Livraria Lello, which turned out to be within fairly easy walking distance.
The unit itself is tastefully appointed, with two comfortable chairs right by the large windows. Each of the chairs is next to a flat surface (table or nightstand), so that you can have a beverage next to you while you relax. Also, the place smells nice. I don't know what's used for scent, but it's appealing.
During my stay, there were a couple of things I needed to ask the host. I used Airbnb to communicate, and the responses were always timely, helpful, and kind.
I will also mention that they have a driver (Carlos) who will provide guests with transportation to and from the unit at the beginning and end of the stay. I found Carlos to be very helpful and communicative. I don't know how his rates compare with other transportation options, but I certainly felt as though it was a very fair deal.
I would definitely stay here again.