I have used this option. It really depends on how booked the flight is. My son and I were not seated together and there was no moving it. It wasnt too concerning as he is a teenager and didn’t care. 😫😫 but if the flight isn’t booked my experience is the agents will work with you. But you are low man on the totem pole so you wait til the end. But $100 is a lot of painkillers so hopefully it’s worth it