Pros
Pfizer's benefits are far and above better than most companies of this size. Included are a company match for a 401K, excellent health benefits with a paid prescription plan, both a paid maternity and paternity leave of 6 weeks, and other health, educational, and financial benefits. In addition to the benefits, the breadth of scientific knowledge is quite impressive.
Cons
Because of the size, politics is very pronounced especially in regards to projects, budgets, and the all important compensation. The lack of leadership has devastated this company and is eating at the core of the company, its scientists. Many excellent people have left for other companies and professions. The strive to please Wall Street and the "shareholders" has hurt the core research with management making decisions to hit numbers instead of doing good science. In addition, a total lack of communication from upper management is quickly decaying any morale and trust the employees have with the people leading our company. Compensation is a highly suspect and a year of good work can be downgraded to allow others to "fit" into a specific bucket or grade. This highly subjective method for grading an employee is demoralizing and doesn't promote consistent performance or giving the extra effort.