We had a great experience in Porto at Carla's loft. The apartment is made in a great new-modern style, really cosy - location is extremely close to city center. We were just walking every day. Carla reserved a private parking for us which was really helpful, meet us at checkin and made a great presentation of the location and apartment + give us some hints and ideas about what to do/visit.
Overall, our experience was great, we do totally recommend this place for couples coming in visiting Porto - great value for money
Roland & Irina