Pros
If you kiss the correct butts, you will get access to good opportunities regardless of your actual skills, talents, and track record.
Cons
If you are not in the very tiny inner circle, you will get an endless conveyor belt of garbage "paying the bills" clients. You will work 60-70 hours a week on crap that is not worthy of a portfolio and get zero recognition for it. You will never get to be on the one team that has all the good clients but you will be forced to come in on weekends for marathon brainstorming sessions that absolutely must result in award winning ideas so they can steal them and take all the credit and reap all the rewards. BUT, as a thanks for sacrificing yet another weekend, you got some free pizza before being shoved back to your grunt work team. So rewarding.