Great location- walking distance from lots of restaurants and tourist attractions. Check in was so smooth, our flight got delayed and a member of staff greeted us late that evening with no late check in fee 🙂 Apartment is not as big as it looks in pictures but still a nice place.
However, because it is so central there is constant noise coming from outside (construction workers, noisy neighbours, music) When we stayed here there was a lot of commotion at night and early morning, making it difficult to sleep. Other than that I would recommend Afonsos place to groups looking for a central place to stay in Porto!