Pros
Some good colleagues and there are a few great managers. There is a lot of room to grow if you're smart and have focus. Good benefits outside of compensation (3 weeks vacation, 2 floating, 3 personal), Work from home is typically allowed, working times are flexible. You can wear basically whatever you want to work as long as there are no clients in office. If you like working "autonomously" this really is an okay job. If you need direction and leadership, not so much.
Cons
There is an insane amount of work. If you are very good at your job the work tends to consistently increase, forever. You're often expected to work Overtime, as much as you can handle. Then sometimes Mercer will decide OT needs to be cut, but there are no resources to pick up the slack and there isn't much support from the managers above the Team Leader level. There is little standardization among the many different client teams so finding solutions to problems is often difficult unless you're on a newly implemented client (And even then sometimes it's not easy). In the Vernon Hills office the morale is pretty low currently. It's been on a down slope during most of this year since the last director left. If you move up internally the compensation and raises are very poor and they blame it on the "rules" for internal promotions. The office is pretty dreary