Delta uses a reservation system. You can basically book going to work something like 5 days ahead, going home from work 4 days ahead and personal bookings can be made 2 days ahead.

This prioritizes work related jump-seats over personal travel. Most guys seem to like the system. DAL does use a seniority based system for non-revs, so seniority pulls some weight in traveling.

On the other hand I could see the senior guys at AA not wanted to give up the seniority system that they have been using for years.

Scoop