Pros
Overall the atmosphere is upbeat. It is a job, and there are downers around, but if you're trying to be a team member, it's not hard to get along with people. Most of the people in management have worked their way there through internal promotions, so although some can have big heads, overall leadership tries to be understanding. Benefits aren't bad, and there are usually decent opportunities to change positions within the company.
Cons
The biggest con I have is, if someone wants you gone for any reason, they'll find a way to get you out the door. Since the company is as big as they are, and the benefits aren't terrible, they tend to take advantage of good workers who don't want to lose their jobs. If you end up going on FMLA or Disability for any reason, make sure to be on top of that information and document as much as possible, because that is a giant beacon for them to use in your termination.