Pros
Everything you can think of that's good and that an employer should have, this company has in abundance. Except, that is, the things mentioned in the Cons section below. It is a great pity, as otherwise it would be a dream workplace for many - just as it was about ten years ago. I recommend this company only if you want to add Amgen experience in your resume and enjoy it for as long as you are given a chance to, not if you plan to stay there long-term.
Cons
Not promoting all people who deserve it. Low transparency of senior management. And did I mention layoffs? Actually, there have been three of them: 2007, 2011, and 2014-15 (still in progress). It is a terribly stressing situation, waiting to see if the axe is going to fall; whoever works there right now shouldn't be envied - at least not that much. Again, recommended only if you want to add Amgen experience in your resume, not if you plan to stay there for a long time.