When I interviewed as part of a group, we were told the average package is about 8lbs. The problem is you never get an average package. Most air is under a pound and everything else is 16+.
Also, no easy shifts, although the overnight here gets away with a lot more because good help for that shift is hard to find. I chose preload because the hours worked for me. It also turns out to be one of the coolest shifts, temperature wise.
Checkers