The communication was friendly and fast, no problems with that. Joanna's friend Nico welcomed us very friendly although we arrived almost in the middle of the night. He was very kind and helpful with everything we asked him about. We asked him about local food and he named us some restaurants after he understand that we do not want to eat Gourmet hamburger and Pizza like in Germany ;)
The flat was great! Clean, comfortable, spacious. There was a basket with fruit waiting for us, a coffee machine and lots of info material about Porto. So we really enjoyed the stay and can highly recommend it!