Pros
The pay is typically better than the other plants in the area of the same type. Not difficult to move up from ground level to management with some hard work and effort. I've seen people go from line worker to lead to supervisor within a year or so. Insurance through the company is a good deal and there are a lot of options for coverage. Free onsite clinic for employees and their immediate family members.
Cons
The environment can be a bit hostile at the plant I work at. This is not due to a company policy or from the big wigs. It's mostly just the people that work there. The production and maintenance supervisors are aggressive in general and can make working there very stressful if you aren't one of the favorites. Favoritism is very big amongst management.