My partner and I stayed here for 4 nights and found the apartment to be impeccably designed and decorated, with amazing river views. It's about a 15-20 minute walk to many of the touristy sights we visited, and has a number of restaurants, cafes, and a supermarket close by.
Susana is also a great, communicative host who gave us nice neighborhood and Porto recommendations that helped during our first visit to the city.
However, I would note that the apartment is beginning to show some signs of wear—there were stains on the couch during our visit, a bit of a finicky toilet, and the apartment wasn't the cleanest upon arrival. These detracted slightly from our stay, but overall we enjoyed it.