Pros
Good benefits, along with training/development opportunities for younger staff at beginning of their career. Due to profile and ability to hire smart people, you get good interaction and exposure to some industry best practices. Strong support of training and education, and due to size, large amount of resources often available.
Cons
High rate of churn of people, moving internally and also out of company, creates instability, which is never addressed. Hierachical decision making and silo mentality. Was making successive acquisitions during years when Oil & Gas division was contributing high profits, and these integrations have a history of being managed poorly. High rate of business restructuring as a result, sometimes every two years, influenced by management consultants (e.g. Booz and BCG). These often lack practical and customer sensitivity checks, and acknowledgement of competitive environment, feeding a cycle of market share erosion and further restructuring/divestments.