We recently stayed at this Airbnb in Porto. This was a 3-day-trip with a good friend. The place looked good, and everything were fine so far, until we have discovered mould around the window frames. We let the host know about the issue. He reacted very well and cleaned up the mould.
Another thing you should keep in mind that this Airbnb don't have a heater. It just supports an Air Conditioner blowing warm air, which isn't enough on cold Porto nights. Better you bring some more layers of sleeping clothes.
Anyways, it was very lovely that the host brought us an iron when we needed one. Cheers!