Avantages
If you're coming from a small company and want to grab experience from a big company to move on in your career, this is a pretty good step.
Inconvénients
Completely dysfunctional environment makes it very difficult to do one's job; lack of leadership and strategy makes it very difficult to know what you're supposed to be doing. Intra-office communication is very poor. Bullying is a problem that is seldom addressed. The CEO often oversteps the responsibilities of his job to meddle in other areas and make it impossible for people to do their jobs, viz., writing campaign slogans for products and insisting that they be used when no marketing strategy even exists yet. I have never worked with a group of people this smart (meaning everyone BUT upper management) who had a harder time doing their job because of the environment that was being created around them.