Pros
I love coming to work every day - Amgen is a great place to be. It's full of really exciting science, and I feel like innovative new ideas and scientific independence are really valued. This is the best biotech company in the world with which to work - strong science, strong ethics, fun people. But on a less high-minded level, I also have to say that the overall compensation package and work-life benefits are far superior to what I know my colleagues get at other companies. Working for Amgen has its perks.
Cons
Amgen's gotten big but still tries to integrate all of the sites, and so having to videoconference every meeting gets quite cumbersome. Too many layers of management too - it can make things a little too hierarchical at times.