The flat was great. Very neat and stylish and quite spacious. We were two families (4 adults, 3 children ages 2, 6 and 8), and we fit quite comfortably. It is very close to some great restaurants by the river bank. I would definitely recommend this place.
The only negative for me was that we decided to use the airport transfer service they offered, but on arrival at the airport the airport transport service was nowhere to be found. At 6:00am, after an overnight flight with 3 young children in tow, this is a bit of a problem, but in the end we managed to get ourselves to Porto City Hosts' offices via the Metro. When I mentioned to them that the airport transfer service never showed up, they did not seem too bothered about it, and there were no apology, which I found a bit strange. In the end I decided to just chalk this up to a "lost in translation" issue and move on. Seeing, that this really was the only negative about this accommodation I would still highly recommend them.