Pros
Chemonics was a great place to get started in international development consulting, by that, meaning primarily USAID contracting. What you learn at Chemonics you will be able to use anywhere else in the development world. It is especially a good place if you go in after undergraduate or undergrad then Peace Corps or right after completing a Master's. I heard that associates are now getting more immediate exposure to more interesting opportunities in the field which is promising which wasn't always the case when I was there. The workload can be overwhelming, but the experience, friendships, and contacts you make are invaluable. Overall, I'm thankful for my experience there, but not sure if it was a good fit for me in the long run at that time at that level. It seemed to me like men were happier there and stayed longer than women. Worth the cons to get at least a couple of years experience.
Cons
High turnover. I hear that late nights and weekends are the norm, now moreso than when I was there. If you have more than a couple of years of experience than that- it can be frustrating because they will take you in entry-level only so you may end up feeling like your experience/education is not valued. It is very competitive, everyone is trying to get from associate to manager because associates are underpaid and often over-qualified for the type of work. Causes a cut throat environment with lots of office politics at times in an already pretty rigid corporate structure. Loyalty doesn't always work both ways.