Marco was a fantastic host! We agreed that I would message him once we leave the airport as it was a late check-in. Despite my message not going through he was still patiently waiting for us at a pre-agreed time and made us feel-welcome at his flat.
Marco took time to tell us all about Porto and places to see, good restaurants, wine tours, etc. even though it was so late in the night when we arrived.
The apartment looks exactly like in the pictures, it was very clean and spacious. We especially liked the original stone wall and the wooden floor.
The neighborhood is quiet in a day-time, but comes alive in the evening. It is walk-able distance to all the sightseeing spots in Porto.
We certainly did not have enough time to explore them all and with any luck will be back soon!

Thanks Marco!