This unit is beautiful, just as the pictures would lead you to believe! Although the pictures don't do the view from the balcony justice - it's wonderful.
The rental is right in the middle of a very touristy area, which was nice for us as we could quickly grab a bite or some dessert on our way to or from the apartment. Yes there was music playing and people talking late at night, but it was never loud enough to keep us from sleeping. We were there both during a weekend and weekdays.
One warning, you have to pay for the spectacular balcony views by going up 86 steps to get from the street to the main floor of the unit.
Overall, it's a great apartment and my wife and I really enjoyed staying here while getting to know the beautiful city of Porto.