Pros
It's a good, solid place to start a career. It generally sounds impressive on a resume (to those outsiders who don't know any better). Also, since it's such a large company you have opportunities to transfer and get a new experience without changing your employer. Job security is almost always guaranteed and as the old shipyard saying goes, if you go somewhere else and "it doesn't work out, you can always come back to the shipyard."
Cons
Some departments are better than others. I've worked in a couple of very professional and normal (functioning) ones, but have also worked in one that was horribly inappropriate and dysfunctional----really rotting from management down. I agree with another review that it is indeed a white collar jobs program and a good old boy network. And I agree with another point----it really is operating half a century behind times and frighteningly, many employees have a mindset that is decades behind. Be prepared for every 'ism' in the book: sexism, racism, ageism, you name it.