If you were travelling J class on a 3 class flight with a reserved seat (does reserved actually mean anything?), are there any benefits of checking in early (online 24 hours before, for example) and would these benefits outweigh any risks of checking in at the airport?
So if I check in early, I'm very likely to get my pre-assigned seat. If I check in late and J class is overbooked, I might get lucky with an upgrade to F, but I could also get unlucky with a downgrade to Y.
What would you do?