I booked my flight two months in advance and paid for a window seat. When I got to the boarding area, I saw that I was scheduled to sit in the middle seat of the middle row. I complained at the time, and was told they could do nothing about it since the flight was full.
On my return home, I have been trying for 2 days to get through to what passes for "customer service", only to be blown off and told to file a complaint on their website. There is nowhere to file on their website! I looked at their FB page and saw NUMEROUS complaints from unhappy customers with worse experiences than I had. Also an article describing a court decision in Spain which showed a tendency on Iberia's part to ignore customer complaints.
Overall, the WORST airline I have even flown. Do NOT recommend!