The Good: Communication with Maria was excellent. She responded quickly to our questions and comments and was always available. Check in with Luis was easy. He also met us at the apartment and stored our bags until the apartment was cleaned and ready for us.
The apartment was clean, had a very well stocked kitchen with good utensils, pots and pans. Centrally located and easy access to everywhere you want to tour (just keep the hills of Porto in mind!). The apartment was very much "as advertised".
The Bad: It is an apartment and so it has all the good and bad of apartment life. The reason for the 4-star rating is due to the upstairs neighbors. Everyday they arrived home between 1-3AM and were very loud. We spoke to Maria about this and she said the apartment above hers was also a rental and the noise depends on who is in the apartment at the time.