Pros
Benefits, salary, professional development, career prospects, international and multicultural exposure. It is a huge company that has been there for ever and will be there for a long long time. Most of the executives come from inside which tells you they have been in the shoes of lower rank members. They are not there for the bonuses in the next few years but they are truly committed to the long term success of the company (which also helps their bonuses, of course, but you get my point)
Cons
Career prospects often depend on your disposition to move around, domestically and internationally. You own your career. If you are not proactive seeking career development they are not going to give it to you. They value employees that are professional and grown-ups. Sometimes the "buddy system" affects you. And sometimes you would feel HR employees aren't either "human" nor "resources" (you own your career, remember that)