Pros
Good portfolio builder. Big name projects with high-end clients. You'll sharpen your skills. If you can work here, anyplace else is going to be like a kid's birthday party.
Cons
If your salaried, the long hours get old. Don't expect to see your family. Upper management rides the mids like thoroughbreds. Which means, jittery AE's and Creative Directors. Very corporate culture. One of the owners walked by my desk one day while giving someone a tour of the offices and said loudly enough for folks in the department to hear "This is home entertainment. It's all going away." I mean, we know that. We're not dumb. But, you've got to walk through the department and just say it out loud, right? Look the place is alright. It is what it is. It's just the hours and the clients are crazy. The stress is killer. And for what? You miss your kid's birthdays, time with your spouse or time with dying parents (I know a guy who was denied time off to visit a dying parent because the deadlines were crazy). So your work can either end up in the garbage bin behind a cinema or in a 5 or 1 DVD sale bin at Blockbuster or Game Spot.