Pros
There are many opportunities to learn, grow and advance at Mercer. The work is hard but interesting, diverse and dynamic. You work in teams but are responsible for your own work, research and learning, etc. So time management and self directed skills are pretty much a must. For new employees - get to know your managers/supervisors and network among the other groups. Find your mentors. They will be your best source for other opportunities and advancement.
Cons
The hours are long for a dedicated individual wanting to advance. So brace yourself. You may need to ask for more opportunity or just dig in yourself - there doesn't seem to be a formal way to advance. And it may come slowly. Coding your time every 15 minutes is a bummer, and part of the Mercer experience - so no getting around that. Pay is okay for entry level jobs and you'll put in a lot of time - work/life balance may suffer.