You need to hang around for 5 years before you can really get the answers to your questions.
I will tell you this: It is nice to go home at the end of the day, and not worry about what some PT jacked up on crack is gonna do on the local sort. It is also nice to stand in the building, knowing that you will be warm and dry all day, watching the drivers leave, with the air temp of 35 all day, and 100% chance of rain.
Each job has it pros and cons. I tried for management, I really did. For 5 years I wrote my letter. For 5 years, I was passed over. After watching one of the best on car sups being told that he had to report the next day to his new job, 150 miles across the state, I quit writing my letters. Plus the fact that I discovered that I am not the type of person to take the **** that comes with being a manager- I am the type of person , that when you come to me with your silly assed problem, I hand you a dime, and tell you to go call someone that gives a damn.
So, after 30 years(3 as a clerk, 18 as a pkg del. driver, and 9 as a feeder driver), I am quite happy with my position at UPS.