Pros
The opportunities vary from office to office, but there is always an opportunity for amazing success. Compensation is top of the line. Many talented associates. Company currently in a transition from a Madmen style work culture to a more progressive work culture thanks to their Northern California roots, but change is slow (national office paternity leave became a new perk).
Kontras
No training... you are thrown into the deep-end of the pool. If you survive, it's a Pro. There is a sparse marketing department that only really feeds the top tier. You must reinvent yourself annually until you find a niche (again, luck & timing). Work culture promotes hoarding of work, work credit, and marketing credit. There is a consistent push to move to management and principle even if the science and research is your core love and talent. Work/Life Balance is tough if your are married and/or have children.