Pros
A very flexible work environment with a big company work pace and resources. Good pay, benefits, and stability. A very large and specialized organizational structure with many product lines provide ample career opportunities for employees looking to expand their skill set or change jobs.
Cons
Monolithic bureaucracy driven by lowest common denominator policies with many layers of departments and management to contend with. Very little opportunity to effect change or see the measurable results to your efforts. Horrible HR practices, poor culture, and very low employee engagement leading to high attrition of talent. Many employees actively using the complexity of the organization and lack of accountability to "rest and vest" making it difficult for the remainder to get anything done.