Pros
This place offers more benefits for part time workers than anywhere else. As a union employee, you get free (and pretty good) health care along with paid vacations and paid days off (after working there for a couple years). I was promoted from package handler to operational supervisor after working there for only six months. As a 19 year old community college students, I was making $350/week, $16/hr for 30 hours a week. I had health, vision, and dental insurance for $8.50/week and a 401k. I gained a ton of experience personally and it looks great on my resume. I left because I transferred to a university and working 5 nights a week with a commute while being a full-time student was making my grades suffer.
Cons
This place is great if you are willing to work HARD. This means that you're (literally) sweating buckets off every night and show the in-building management that you're a hard worker. This isn't necessarily a con, but from my point of view, the high turnover rate is because most people aren't willing to really bust their backs for a job that only starts you at $10/hour, which is fair. If you stick with it for a little while, you'll go far. If you're trying to make a career out of it, that's another story. To move from hourly employee to part-time supervisor is generally a pretty quick process if you're a good worker. To make the next step and become full-time, you have to work as a part-time supervisor with pretty small raises for years. Most of my full-time supervisors worked at UPS for at least 10 years before they got the promotion. When you become full-time, you work crazy hours, but make ~$65,000 a year with no college education. The majority of part-time supervisors are competing against one another to try to get promoted to full-time, which rarely happens. The other route to go as a long-term career is to go driver. Given, I don't know a whole lot about this process, but I do know that it's the same story as trying to move full-time. It takes years. Then when you do get the promotion, you only work part-time through peak season and they put you back to your original position. Deal with that for a couple years and you can have a pretty good, secure job to make a career out of. The last con that I've mentioned many times: this is HARD WORK. Especially during the dreaded peak season. You're expected to meet pretty high production standards for 8 hours a day during peak. Given, the pay is awesome because Union employees make time and a half after five hours. Part-time supervisors get paid for all the hours they work too. But man, this is a ball-busting place. Easily the most stressful job I could imagine. If you can handle it, awesome. If not, don't bother. You won't last long. Another minor thing: you have to really commit to the Monday-Friday work schedule every day. They do not give a lot of days off and if you can't work every day every week then they won't hire you.