Pros
JM has a great history, stretching more than 150 years. Established well in their industries. Quick climb from entry level to mid level. If you have ability, will definitely be used. Part of Berkshire Hathaway.
Cons
Tends to be fast followers in industry, very risk adverse, very flat starting at lower management level. Mid-management tends to have to bear all the risk, but not given the tools to really impact outcome. Out of touch with cost of living in Denver (impacted by transplants from CA). Tends to remember mistakes long term, regardless of addressing them/fixing them/growing from them. Inflexible about hours/work life balance. Had ten different managers/bosses in six and half years. Bad experience with double talk/not the whole truth.