Is it good to have Pestana membership for hotels in Portugal? Is the membership free?
and were is the best location to stay in Porto if we stay only 2 nights? hotel how is Mercure porto centro?
Maybe too late for you, but I got the Pestana membership before my trip in June, and used it to stay at the pousada in Sagres. Eventually I unsubscribed from their marketing emails but the membership was useful for the booking.
As for Porto, we stayed at the Hotel Carris Ribeira, nice location, good prices when we booked, nice place.