Change of seat is unwelcome
Svantaggi: I had reserved and paid for a certain seat. Upon boarding I have been notified of a seat change, presumably to better accomodate someone else. The new seat was in a front row with a wall in front of me. As I am a very frequent traveller and as I am quite tall, I had reserved another seat with care so I could stretch my legs during the 9 hours night flight. But with this forced seat change I really was uncomfortable.