Pros
Big name, big name clients, Edelman perks such as happy hours, free food, learning opportunities, etc., can become friends with coworkers. You're seldom not busy. HR is on top of their game.
Cons
Passive-aggressive and competitive coworkers and superiors, insane deadlines, no work/life balance, low pay, no potential for upward mobility, sometimes boring work. Lack of communication. Not everyone but a few do the people I worked with were immoral thieves and overcharged as well as manipulated their research. I had 5-7 bosses in a year and wasn't always clear on who I was reporting to. My boss would make me feel guilty very time I tried to take PTO. I never took all of it because I was too scared to. I was scared to ask for time off for doctor's appointments as well. If you don't eat lunch at your desk, they will think you aren't working hard enough. If you only work 8 hours a day, then you are not working hard enough and may be talked to about it, despite not getting paid enough to match the hours they want you to work. Be warned: this is a mill that will burn and churn you. I'm the type of person who thrives in collaborative and harmonious, not competitive environments. Edelman Berland broke me. And I saw it, and Edelman, break many of my peers. If you want this type of environment, you might as well go into investment banking and at least make money equivalent to the number of hours you are working and the crappy life you are having.