We enjoyed our time in Porto and in Maria's apartment. It's exactly like the photos. Very bright, new and clean. We love the decoration and the energy (especially since it was raining most of the week).
We never met Maria but she was very nice and helpful through emails.
The apartment is conveniently located close to the train station. 10 mins walk to reach the city center and 30mins to the river front. You get to see most of the sights along the way so I would suggest walking.
The internet was a bit slow when we were there (unable to stream a Youtube music video at times). We work online so this was a bit inconvenient or us but it wouldn't be a problem for anyone else. I would recommend staying here.