An absolute 10/10. Sunning location with a river view and a normal-sized balcony (rare thing for Portugal :)), which was a great spot for evening meals and wine. All places of interest are in a walking distance, never used any public transport. The apartment is stylish and well-equipped, the bed is by far the best we've encountered during our travels. We were vey welcomed by the host, who also provided us with a detailed guide on Porto, both well-known touristic venues and hidden gems of the city.
Highly recommended.