Pros
I have to admit that I learned more working at JM in any given 6 month stretch than I did the entire time I was in college. They genuinely do try to develop their people, and promote from inside the company... as long as it is a production position. It's a whole different story on the salaried staff side.
Cons
There are many: - A toxic culture that focuses more on who to blame for problems then actually resolving or (gasp) preventing the problem in the first place - Crushing workload... Be very careful with what responsibilities you accept working with JM. If you touch something once or accept a task, then it will be yours to handle for the rest of your time in the position. If you do well in your position in the beginning, management will continue to pile on more work. Then, once you stop being productive due to the amount of work put on your plate, they will start giving you bad reviews and drive you out. - My position required very little travel when I started, but as the position changed, I started having to travel a lot and had a significant increase in workload. I was never given compensation for the additional work. - Upper management is very hit or miss when it comes to competency. In my department, it as pretty much a long string of misses.