We have 2 major complaints: check-in and wifi.
We were never given any information on the check-in process, despite telling the staff our estimated arrival time. Upon arrival the host tried to remotely buzz the door open, which did not work. We stayed in the street with all of our luggage for almost an hour after arrival before someone finally came to open the door. My parents have difficulty standing/walking so this was quite tough for them. Also, it was the only day that we could catch a nice sunset in Porto and we had timed our arrival for this, but missed it due to the check-in delay.
Wifi never worked at all. This is an issue for travelers from out of country, also for those like me who also need to work remotely while traveling. The host asked us if we could be home the next morning for Vodafone to come resolve the issue— during our vacation? Not possible.
Other than the above complaints, the Airbnb was wonderful- spacious, clean, great location, well equipped, and comfortable. It was otherwise perfect for our family of 5 adults.