We had a great stay at Celso’s apartment. Very spacious and clean. Celso was very welcoming, although we didn’t get to meet him we did meet his wife. Great communication with quick responses to any of our messages. We would highly recommend staying at Celso’s apartment.
One note, if you are looking to be close to the tourist attractions in Porto; I.e., within walking distance, then this apartment may not be what you are looking for as it is about a 20-25 minute drive from central Porto.