Pros
You get to travel to some fantastic places, but only if you work in a regional--rather than a support--unit. It's a great way to see the world and travel, but do not fall in love with project management, new business, or support position rolls. Instead, use this organization to go someplace else.
Cons
Chemonics is one of those companies that keeps falling but never hits rock bottom. The management--especially the executive management--is white male dominated even though the rank-and-file is not. The company doesn't manage itself well: financial management is terrible, innovation is nil, and HR is a joke. Also the pay is terrible. This is a company that hires people with top-level grad degrees and has them process expense reports or timesheets. Let me be clear: you aren't actually doing development; you're just supporting the people who do. So don't get fooled into believing that you'll use your MPH to fight AIDS or your M.Ed to teach children in Ghana what to do. Take your degree elsewhere.