Pros
On the surface, potential to move around and into different disciplines is exciting and seems attainable. Their potential to provide consumer and shopper insights through, and from, a variety of media and platforms is valuable for clients and employees. Good opportunity to learn market research/analytic skills - a good platform from which to jump to another company.
Cons
Although they are a public company again, ever since the PE people took over they have created an atmosphere of mistrust and deception. I don't think they want people to have a long-term career there. They have substantially reduced their pay ranges and potential salary increases for the vast majority of employees. 2% is most common if you can get that, and people have to wait more than a year for that so it's not really 2%. But, Mitchell Habib gets a 17% raise on his base salary of $675k. Whether or not he deserves it is immaterial - senior management has misrepresented "we're all having to take cost-cutting measures". Departments are still very territorial and it is very hard to move across disciplines. Very "cliquish". People seem to really dislike working there now. Company usually does not back its employees.