Pros
The focus on long term value creation versus short term (which often occurs in publically traded companies - speaking from experience), the ability to innovate, experiment, and drive creative destruction without the fear of failure provides for a very positive environment. Working for an organization that puts 90% of the profits back into its operations is motivational. Having the resources to drive continuous improvement is exciting. Anyone interested in exploring a career with a Koch company should obtain a copy of the book "Good Profit" and you'll get a better understanding of how MBM generates a culture that allows for personal growth and fulfillment.
Cons
Not sure I can list a con. I would add if you are looking for something easy...probably not the right place to apply.