The flat is not centric but easy to get to the center by Uber or even walking (25 minutes). The subway was very close by, but since going by Uber was so cheap we didn’t even use it.
The neighbourhood is very quiet, one decent restaurant close by and a very good pastry shop, which we visited every morning.
Miguel himself wasn’t there on the arrival but his parents were very helpful and nice, showing us all the apartment and trying to answer all our questions about the city (which were many).
The apartment is big and spacious (we were 8 people and fit with no problems whatsoever). The hosts were kind enough to turn on all heaters before our arrival so the apartment was very warm. All beds are comfortable, and the apartment is well equipped (enough towels, appliances, etc...).
To say something I would have liked an extra shower (one is very small and one is big) and maybe some wall decorations, since it was all very white, however that's not of utmost importance.
They were very nice to wait for us on the arrival (our plane arrived at 10pm) and they let us stay in the apartment until departure time. I would definitely recommend his place and if we go back to Oporto with a group I would go back to Miguel’s apartment.