We had a great time staying hat Merc‘s place! I’ve been to Porto a few times and this Airbnb had the best location. You’re very close to great restaurants (Intrigo, Pregar,…), as well as to the water front and the old town. You can walk to all the great spots! The kitchen is well equipped so we were able to make breakfast for ourselves. Definitely will come back!
Just be aware that the apartment is a little bit badly soundproofed so you can hear everything from the stairwell however, everyone tries to make sure to be quite (there are also signs for all the neighbors to be quiet after a specific time).