Pluspunten
Job stability. An extremely stable company that you do not have to worry about being laid off. It is especially great in a down economy. Friendly people. The people I have met in this company so far has all been friendly to deal with. Flexible schedule (at least for IT positions). I have been able to take the time off whenever I needed it. Many available jobs to choose from (depends on your position too). UPS is a large company and it has a great variety of positions if you have the skills to do it.
Minpunten
Compensation below market (you pay for stability) and not based on performance. Difficult to advance (at least for IT positions in certain groups). Company culture/traditions maybe too ancient for the younger generation.