We traveled with 3 kids in august 2019.
This place is perfect ! (and we've seen many airbnbs)
Location is great, not far from the walking street and cafe majestic - highly recommended for a stylish and proper cup of coffee.
The apartment is beautiful, recently renovated, huge and spans the whole floor with a private elevator stop into the apartment and it comes fully stocked with everything you'll need. You will need to go down several stairs from the street level to the lobby.
The living room is great however the kitchen, although it has everything, is pretty small.
The apartment is on a top floor, well lit with many skylights, large windows and two balconies.
Beds were very very comfortable with pillows of several types.
There's A/C in each bedroom and the living room which is essential in august (if you're not european...)
If you come by car, there's plenty of temporary parking to unload your bags, but consider you'll need to park in a garage 2 blocks away.
We will definitely book again when in Porto.