Pros
You might make a friend? You will understand what working for a bad company means.
Cons
Extreme burnout. No work-life balance. Extreme politics. Work effort means little unless you know how to play the politics. Low pay compared to other companies. Mediocre benefits. Very focused on appearance. Your clothing choices matter ($200 outfit v. $50 outfit). Your car choices matter (BMW/Audi v. Honda). You physical appearance matters (thin v. overweight). Very micromanaged. Inappropriate manager-employee relationships. Very "stuck-up" culture. Feels like high school. Introverts will never get promoted. Don't get sick. You will still be expected to work. If you do get sick, it better be terminal. Management through humiliation. Feedback often tears you down more than it builds you up.