Terrible customer service. They had my luggage in their possession for four days - nobody was able to give me a point of contact to get it delivered or picked up. When they finally sent it out for delivery, the driver showed up at the wrong time which led to a new day of delay. Once again nobody knew how to figure out how to gain access to the luggage. Never again!

Not very professional customer service, lack of of accuracy in given information, less confidence of what they are saying, and low care about their customers.
It is not the ideal choice to pick your flight with unless there is no other better choice.

Knowing that Iberia had a rather doubtful reputation in the past we did choose this airliner because it was the best option for us.
Must say that all went very well, the booking, the price (!) the cleanliness of the plane, the staff, the punctuality and the seat comfort, BUT, note that we had booked Economy Comfort, means XL seats.
Two legs flight, Brussel to Madrid and then to Fuerteventura.
Madrid has a great airport, we could find our connecting flight very easy, the same when we returned.
Have booked already to Gran Canaria for next June :-)
PS : I'll copy this review to the IberiaExpress reviews because second leg was With IberiaExpress.

Worst airline I have flown with. They over sell the flight then don’t let you check in online the day before. When you get to check in at airport they put you on standby and say you have to hope no one turns up for the flight. Stressful and not acceptable. The airport staff are all unhelpful and rude, evidently working for this airline and dealing with the torrent of customer complaints is a miserable task.

The flight was delayed and then the ground staff was very rude, snappy, and abused their power. Would never fly Iberia again.