It's not an easy job, and it isn't for everyone. Once you push through it you're getting good money for part time work, and if you're on the manager's good side they'l let you stay for more hours. Advancement is common within one year. Package handlers often go on to become managers and high level staff quickly. Work hard, get fit, benefits are paid for and there's even a school incentive program.
Women and women of colour are encouraged and often surpass their male counterparts in determination and becoming high level staff. Regardless, everyone seems to be treated with respect while I worked there.
The hardest thing is the willingness to get up and bust your butt that hard for another day but if you can stick with it then it's worth it and if you work hard enough it'll pay off in the long run, you can make a career here if you want to.
Management is OK, just like management anywhere you have to play the game, however everyone truly cares about safety and it's ingrained in the culture. Weekends and holidays off with the occasional optional weekend/holiday offered for more pay.