This was probably the nicest AirBnB I've ever stayed in, the apartment was just as beautiful - if not more so - than the photos. The Juliet-style balconies are a romantic and elegant touch (and practical to boot, they can open up like windows to let lots of fresh air in). Luis Filipe is a really nice guy, wonderful host, always open to communicate and lend a hand if needed.
Luis' apartment is very close to the city centre, only a few minutes walk, which made getting around town so easy (that and quick access to the major Trindade subway station). Markets everywhere, shops, cafés, and cute restaurants/tapas joints just down the street. And only 15-20 walk to the magnificent Douro River.
My wife and I could not have found a better place for our honeymoon, in terms of city and lodging - we highly recommend that when you come to Porto, talk to Luis Filipe.