Had a lovely stay at Casa das Manas. Appartment is exactly as shown in pictures, and is situated in the city center so you can walk everywhere. You have lots of cafes, bars, restaurants near the appartment, even the nightlife is 5 mins away. Diana and her mother went out of the way to make me feel comfortable, and theye were always available if I had some questions.
Will stay there again, as soon as I'm back to Porto! :)