Pros: Great location and space look aesthetically good. Communication from the team with check-in and concerns were answered quickly and able to help us with most concerns.
Cons: The space has a musty smell that just doesn't go away, this is not the fault of the owner as it's an old building and there is essentially no ventilation of any kind. You can kind of offset it by putting on the airconditioning, but then the space is ultimately too cold and the moment you turn it off you'll get the smell back. The bathroom also has a sewage smell that doesn't go away -- I experienced this at another AirBNB in Lisbon so not sure if it's the older buildings and pipes in Portugal or if this is something that can be handled by the owner.
All told, the value of this place is pretty good and the location is waterfront -- although if you haven't been to Porto before, you will have to walk up a large staircase or take the tram up the mountain and that's where downtown is so be ready to walk a lot of stairs which you may or may not like.
Certainly as an American (who has used AirBNB a lot) there can be cultural differences in what we expect and I've traveled enough around the world to appreciate that. Downsides were that we didn't have enough pillows, pillow cases, or blankets for 6 of us at the house, although the house was listed for 6. By night two the company had brought more pillows and a blanket, but not more pillows. There was also only two small Toilet Paper Rolls and no body or hand wash on the first night (for a 3 night stay) - and again the company fixed this by the second day.
The floor after walking around the apartment for a few minutes made all our feet black with dirt, which just didn't inspire confidence that the place was cleaned properly, and even after asking, and they said it was cleaned -- the dirt was exactly the same.
All told the place is liveable for a few days if you can put up with the musty smell and the dirt -- if you are looking for a more luxurious experience this place may not be for you.