Avantages
Large international company with opportunities to network globally. Very knowledgeable people (if you can track them down and connect with them) in a wide variety of businesses. Stable job. Good "starter company" to prepare you to work elsewhere.
Inconvénients
Very poor communication between departments, branches, divisions or countries. You will be re-inventing the wheel. Jealousy & competition between branches is discouraged in word, but encouraged in deed. You must be very careful who you help or very secretive if you do lend a hand to another branch. No chance for promotion. If you're hired on as management then you have a chance to move up, otherwise the company will hire from the outside before they promote from within. Little direction from management on where the company is going. Bureaucracy. Stagnant culture. Zero ability to implement change on a local, national or global level. Very low wages compared to similar positions with other companies.