Pros
Edelman is recognized as one of the world's leading PR firms. You'll learn from some of the brightest in the business. You'll also have the opportunity to work on some of the world's best-known brands that are held by companies with large marketing budgets. Richard Edelman, the company's head honcho, has a future-forward vision of the PR and marketing communications industry. This vision echos throughout the hallways and trickles down to junior staff. The company has practice areas in nearly every industry and offices around the globe, which is a plus for those who may want to explore other areas of PR.
Cons
As in any advertising or PR agency, management is promoted based primarily on the ability to bring in new business or for the success/growth of current clients. But a good PR person isn't always a good manager -- so there can be a culture of ineffective and inefficient management on some teams. Be prepared to work long hours and remain constantly tethered to the office and the client. Client demands are high and the grunt work usually falls to the lowest of junior staffers. High burnout (and high turnover) is very common here. In my experience, turnover was higher here than at other similarly-sized marketing communications agencies; that's a red flag in a high churn-and-burn business.