Pros
Senior leadership does what they say they will do, and has managed to avoid management fads and "flavor of the month" changes in direction. They've stayed consistent on some people issues for 3-4 years. There is a strong knowledge that they are in a cyclical, commodity business and the finance people have done a great job weathering the recession with creative ways to avoid layoffs. Employees at all levels are hard-working folks, generous with their time, and genuinely want to help each other out. It's a hard-working, relatively flat company that is growing and there are many opportunities to work on challenging projects and to take on a lot of responsibility. Plus, a lot of employees can get behind the official mission, "To help the world grow the food it needs."
Cons
While there are a lot of project opportunities and responsibilty, the company culture is quite traditional, and may rub Millenials the wrong way with its limited work-life flexibility and hierarchical decision making procedures. It is an engineering-driven, "Minnesota Nice" culture that does not encourage conflict, and creative types may find it a bit stifling. The company is still working on the last bits of bringing together the two companies that merged to form Mosaic, and there are still some spots where there are "corporate vs. the field," or "the way we need to do it vs. the way we've always done it" issues that get in the way. Also, the hiring process is still being improved, and it can take 10 weeks and multiple interviews to get through from initial job application to an actual offer; be prepared for this, if you are an applicant.