We had a wonderful stay at Manuela and Carlos' apartment. It was right in the center of town very close to the train station....which was very convenient. (Perfect location)
It was nearly new, having recently been renovated, well decorated, comfortable bed, hot water shower, small kitchen with everything we needed to prepare breakfast.
Manuela was a very accommodating host letting us leave our luggage and check in early, having maps of the city, good recommendations for restaurants and places to go, things to do.
We would definitely recommend your staying here. My husband and I are also Air BNB hosts, and know what it takes to make guests happy.
If we're ever in Porto again....this is where we'll stay!