The stay was perfect. Communication with Margarida is at the best, reactive and with useful information.
Procedures were also made very flexible and gave no issue at all, even when we arrived late in evening/night.
The flat is as shown on the post. It's nice, not far from center, we did many time by foot without problem.
The balcony with the morning sun is great.
Porto is worthy to visit. Many nice buildings, history, interesting museums, and amazing food options.
With a sunny warm weather, most of it can even be done by foot (with several circuits over several days of course)
Conclusion : if you go to Porto, and you should, don't hesitate to stay at Margarida's place, that's all you need :)