The good things:
location is very central, close to the metro station that goes to the airport and not far from the historical city centre; also has a lot of cocktail and brunch spots closeby. overall it was also quite affordable and the room itself was clean.
The bad things:
the bathroom is a bit of a trek from the room and it's very old and due to that seems rather unclean; in the evening there was also always a huge puddle of water on the floor.
The doors and walls are incredibly thin, so you can hear everything that's going on in the staircase as if it was happening right next to you. There is also no fan in the room so if you want to have some air to breathe during the night you have to keep the window open, and it's rather loud due to the people leaving bars and such. It also looks like the price on airbnb was rather inflated compared to prices listed at the hostel itself, but I guess that's how it usually is. The hosts also didn't really speak English, but it was possible to communicate with them nonetheless for basic stuff.
If you're looking for a relatively cheap place in the centre of Porto, it's still an okay deal - but it's good to be aware of the few issues