Pros
Ogilvy is a great place to gain experience, but a really difficult place to gain recognition. Employees really develop critical thinking skills, and learn to look at the industry through various lenses. Ogilvy has a great work-life balance, and tends to be humane in the way it does business and treats employees. A comprehensive benefit package can make up for a lackluster compensation - take all benefits into consideration before accepting a salary offer!
Cons
Ogilvy is slow to promote great talent, and loses employees as they move to different agencies for recognition. Often, more effort is placed on retaining poor performing senior management and executives. If Ogilvy placed a bit more effort on retaining some of the bright and shining stars as they rise through the ranks of account and creative, they might be able to build some great home-grown talent.