Pros
Its steady employment. The projects are interesting and impressive. The people you are in the trenches with are smart, good people who will never be promoted, just like you. Good benefits, which is why most of us are still working here.
Cons
You are a # and not a person, kind of like prison. Run by accountants and they will constantly remind you that you are screwing up 'their' budgets. Those projects that are great are consistently run by inexperienced and bumbling leaders who will drain the budget, make terrible decisions, and/or do nothing (if your lucky). This is a giant corporation, run by people who are very proud of creating this conglomerate through mergers and acquisitions, but whose leaders have no experience in running a giant corporation and its really obvious. Expect major rebranding, reorganization, shuffling of staff every two years. It gives the presidents something to do. When you are hired, get the salary you want then. You will be told from then on that you should be grateful for your job, you can easily be replaced and your lucky if you get 2-3% raises that don't cover cost of living increases. But its all corporate's fault and no one can do anything about it - which isn't comforting. Ever see that article "10 Things Bad Managers Say"? Expect to hear at least one of them everyday. If you see a happy slogan promoting something chipper on a poster around the office(i.e. "Celebrate Diversity", "Go Green", "Promoting from Within"), the opposite is going on. It's a running joke...