Amazing stay, cleaner than clean and with comfortable (sleeping)couch and bed. Perfect for our 8 day during stay. Marco and his wife answered so quickly on our messages and gave us amazing tips. The location is perfect, with nice restaurants for breakfast and diner closeby. I do must say that the walls are so thin you could hear the neighbours talk as if they are in the same room. At night, we didn't hear them at all which was nice, but if you want to sleep in you should bring some earplugs ;)
Eventhough I 10/10 would recommend this apartment and Porto in general.