Amazing stay. Really nothing short of that in summary. We were 3 adults and 2 children and the place could have easily accommodated more. Generous room sizes and a well appointed kitchen / living space meant that we all had privacy when we wanted it and were comfortable when we were together. The location is also perfect. The gaia side of town is a bit less touristy with easy access to port cellars. Tiago, who met us, suggested that we eat literally downstairs at the restaurant next door. We loved it so much we ate there both nights. Simple, local food - nothing glamorous but my kid loved the clams and I loved the lamb chops. Great local wine, of course.
There's one small catch: parking. There is a parking lot almost next door but it is difficult to get to and we ended up driving around a bit. Still, I view it as part of the process and really nothing to do with the place itself.
Fabulous time and would definitely recommend Porto and this apartment to friends.