The apartment is just great! We have been there for one week and it cound not have been any better!
The area is great and super close to the city center. We done whole Porto by foot... really great.
We had a car for the area around Port and there are heaps of over night parking spots around. (Night parking is free between 8pm - 8am... all other time max parking 2h for 1€).
If you ever go to Porto, thats the best place to stay ;)