I had an amazing time in Oporto and the apartment most certainly contributed to my wonderful time. The location is absolutely glorious as it is a few steps from Sao Bento station and a few steps from main bus routes. The apartment is beautiful and just as shown in the pictures. It is clean and has everything you need (wifi is very fast).
The only things to consider is the outside noise which is rather loud and all night and the bed is a little uncomfortable so if a nice bed is a must for you I would think about that.
Other than that the apartment is an top tier option to stay in Oporto.