From all my experiences with AirBnB and similar services João is by far the best host and his apartment among the best I've ever stayed in.
Not just because the apartment is spacious, comfortable and decorated with good taste, or because you could smell the cleanness in the air (literally), or the beautiful garden on the back where you can enjoy the sun while drinking a nice cold beer, but because you get all this after having the worst experience in a previous place with another host who didn't even try to fix things, you have your wife and your 3 years old daughter with you, it's 8pm on a Friday and the guy just runs ahead to make sure everything is in place to welcome you and your family the way you really welcome a guest. So if you are visiting Porto and it's surroundings and you find one of his places available and you like what you see, go and get it cause you won't regret it.