Pros
Diversity (it is like UN), top notch people, flexibility, stable. Many people committed to great cause but with business mind. No tax on your income. Many vacation days. Flex arrangement when needed and you are performing (telecommuting, reduced hours, etc.). Unless you are on a contract, people don't really get laid off or fired.
Cons
Too much international travel, office politics, bureaucratic, often expected to work 24/7 due to different time zones involved. Very slow promotion. Diversity including gender is emphasized but still male dominant work place. Your experience totally depends on your managers/directors. Different job contracts, some are permanent and some are only 2-year and it doesn't really depend on your ability, more to do how and when you enter the company. There are a small number of employees who are not motivated but are just there to retire...