Pros
Important mission. Mostly ethical management. Some extraordinarily talented people and committed people. Excellent benefits and, depending on where in the company you sit, usually great flexibility with respect to work-life balance. Philanthropically generous.
Cons
While there are some exrtraordinary colleagues, there is staggering mediocrity hiding within a still-bloated organization. Highly bureaucratic and hierarchical, it can be difficult for innovative and dynamic leaders to find their way. It can be exceedingly difficult to move within the organization across functions or divisions. Neither performance management nor talent planning is done particularly well. Despite the rhetoric about world-class science, the company feels as though it has given science backseat for the last decade. Rather trying to innovate growth organically, Pfizer has become purely a deal-making machine. This can be more than a bit demoralizing for those who came to the company to engage scientific discovery with the best; the best scientists, I'm afraid, are elsewhere. The fatigue associated with the constant merging and restructuring and right-sizing is definitely taking its toll on staff.