Pros
Great benefits, you can learn A LOT depending on your department and supervisors, options to travel and meet people from different cultures, place to make friends and built community, and if you agree with the mission, can be meaningful work.
Cons
Poor pay, very flat organization and little opportunity to gain significant promotions. Very demanding work for too little money. A bit of sexist workplace as in men received much more ability to have opportunities. VERY nepotistic and favorites played often. HR didn't get very far with complaints either.