Its not just about how much work you can put it. You really need to network your way into the company. If you can't compete in terms of networking, personality, and likeableness, then you're not going to move up in the company or get noticed. Expect to really go out of your way to kiss up to your management.

Stress, stress, and stress. The company is full of smart people, but everyone is always competing against one another. The hours really get to you and you feel like you can't ask your peers for help. If you don't figure out how to do something on your own, then the management will pull you aside and speak to you personally.