Pros
It is a recognizable company with good branch power. It is great for college graduates just starting out and needing a good stepping stone. There are plenty of positions available in various fields within the company, so there is definitely variety with what you can do. Management, depending on the location, will normally watch for employees with potential and groom them for upper management or an appropriate place in the organization. Although it should be said that once one gets to a certain level in the company they may have trouble with the politics of the organization and defending the company's moves.
Cons
It is very political and many times good people get cut. Wages are low, and lower level employees are put upon heavily, much more so than their position warrants. The company also has a large hierarchy and structure putting more stress on the lower level employees. Just like with all companies, everything flows down... unfortunately, the people at the top turn a blind eye to many things that go on in their organization. Some parts of the company are worse than others, but it could be said that this is true in most cases. It is not the most productive environment.