Pros
There are countless opportunities for you no matter your interests. Many of the people I've talked to started in a role that was based on their college degree, but transitioned to a completely different area based on their interests. Supervisors are continually asking what your career interests are and are helpful in getting you to a place where you will succeed. You will be recognized for the work you do. Koch believes in rewarding employees who provide value, and does not believe in rewarding those who merely "get by". If you are putting in a lot of effort, the company is good at recognizing/rewarding you for it. A lot is expected of you, but with that comes trust. My experience has been that I haven't needed to take any vacation/sick time if I'll just be missing a few hours for a dentist/doctor appointment as long as I'm getting my work done.
Cons
Because Koch has a high standard for employees, roles can remain unfilled for a while after an employee retires/quits/is terminated. Our of necessity the role is absorbed by the people in that group while a replacement is hired, but this can sometimes lead to the role being eliminated and the work staying with the group. This can work out, but can often lead to increased hours for those who have taken on the responsibility