Pros
Amgen pays very well and although in recent years benefits have been decreased (downgrade in health insurance and stock purchase plan is no longer worth participating in), they remain superior to benefits from competing companies.
Cons
Advancement seems to be less dependent on excellent job performance than it does on favoritism. Requests for vacation are frowned upon as though you are abandoning the company, and it is not uncommon to be asked if you still need a certain day off, several weeks after the vacation was approved (the implication obviously being you should cancel your pre-approved vacation). Each employee's end-of-year ranking is based more on meaningless metrics that have little or nothing to do with productivity. Any hint of criticism, no matter how constructive or logical, to the ideas of leadership or leadership's favorites is seen as having a negative attitude and not being a team player. This reputation sticks with employees forever. The result of this is a site-wide mouth shut policy with no open dialogue. Much work occurs on projects for which the only purpose is to keep people busy. The employee review and internal hiring processes are highly secretive, with most outcomes coming as complete surprises to everyone. When an outcome is negative, affected employees are usually not told, and must rely on hearing it through the grape-vine from their peers.