The stay in Catarina's apartment was outstanding. Communication was easy and checking in, too. After showing us around in her apartment, which was very clean, she sat down with us and gave us a lot tips of where to go and where to eat and online she sent us even more tips. With so many good suggestions even if you're in Porto for 2 weeks, you couldn't do everyone of them.
The apartment was right in the middle of Porto, easy accessible with metro from airport or station and the city center was within walking distance.
Although it was May weather was a little colder than expected, but Catarina had a heater prepared already, which made the room warmer at night.
I would definitely recommend staying with Catarina and when I am in Porto the next time I will do as well.