Pros
American Express definitely isn't afraid of offering the compensation that an employee is worth, and recognizing strong performers on a regular basis. Management seems legitimately interested in keeping up moral with frequent events and projects. The environment is constantly changing and evolving, which keeps things fresh and interesting if you're flexible enough to learn a new job every few months.
Cons
Adherence to policy and procedure comes with no exceptions. If you try to make an argument that you've got a better way to do something or need to step out of procedure and have reasoning to back it up, you either never hear back, are instantly rejected or it takes so long that the issue becomes irrelevant. My personal record is asking my boss for permission to talk to another department, whom I asked for permission to talk to the department above them. Once I made it to the top, they reviewed my request and gave permission for the lower department to give permission to my boss to give me permission to actually do my job. If that sounds incredibly confusing and frustrating, it is.