Part time employees have, in the past, been granted access to the same benefits that drivers receive, including health, dental, vision, life insurance, legal, and pension related benefits. Dental, for instance, is covered without even a co-pay, though the health has minimal ones. In Washington State, there's a choice between Blue Cross Blue Shield and Aetna for the health and dental as of last year. Domestic partnerships are covered as well, and so far without flaw in my experience, within the state by UPS. The extension of benefits are generous in scope, and are rare this day in age, thanks to Union bargaining.
It used to take years to advance beyond a part time position to a driving position, but within at least the Redmond, Washington Hub (and likely Seattle and Everett Hubs as well), advancement to a driving position takes a year or less based on seniority - in the past, it took four or five years at times, as they are good jobs. However, part time employee retention is very low (over 100% attrition per year), so advancing in seniority is quick. With displays of competence, changing positions within the part time fields is easy as well - from Loader to Unloader, Irregulars, Smalls, Sorting, etc, are transitions usually with little wait time, and often add some additional pay ($1/h additional for Sorting, for example).
Attendance policies for Part Time Union work is very lax - for Loader/Unloaders especially, no-call no-show events are rarely punished, in order to retain employees. Supervisors are at the opposite spectrum, and can expect to be fired for a similar event, or even strongly discouraged for calling in sick. After a year, sick days amount to a week's worth, along with a week of "Option" days which can be taken just like sick days, and two weeks of vacation, even for part time employees. You can expect not to be allowed to take vacation or option days towards the end of the year, during busy season. For Part Time employees, labor past 5 hours is considered overtime, and you're provided one 15 minute break, or two if overtime extends particularly far. Lunches are optional, but unpaid, and are typically not taken by part timers at all.
College tuition help for Part Time union employees is at $3,000 from the Earn and Learn program, which comes in the form of grants. However, they seem no longer to be tax exempt - yet in the past, personal experience has seen the full sums granted without issue. This involves registering what classes you wished to take online via the Earn and Learn website, and at the end of the quarter, faxing your info to them, basically a statement of your grades and the costs. If approved, you receive a check up to $1,500 dollars a quarter, to a maximum of $3,000 per year, for as many as four years. Similarly, loans are available which, so long as you continue to work at UPS, will see their principal paid off by UPS itself. If you leave, expect to pay the whole thing back - and either way, you do have to pay the interest on the loans as well. The interest is very high, 14% or more, and you should expect to pay more in interest than in the principal by the end of the loan term. This seems to be handled by Wells Fargo Bank, at least in Washington state.
Another minor perk, at least when doing a job like Loading, Unloading, or Sorting packages, is the permission to wear personal music players and listen to them. One headphone should be off one ear, but otherwise you're free to fill what is otherwise repetitive work with books on tape, music, radio, etc, so long as you can still hear when being called. This, of course, does not apply if you advance to management, and the trucks do not have radios.
Safe working records are rewarded to whole shifts of work by BBQs of increasing scale the longer a safe run occurs, wherein free hamburgers, hot dogs, chips, soda, etc, are provided at the end of a shift. Awards theoretically go out monthly for best work group members, and best shift member, but this happens unpredictably as well. The schemes for rewarding employees or work groups based on performance has varied widely in the two years I've been employed, and sometimes are non-existent. They range from sports drinks to pizza parties, depending on the time period and achievement, though consistency is not to be expected.