Some teams have very good people and culture, and it's a joy to work with them. The compensation is good as well.
Cons
Overall, not a good place for engineering. Extremely risk averse and process heavy. People rise in the ranks based on tenure and personal relationships rather than ability and contribution. The company culture does not promote openness, honesty or collaboration.
Financially rewarding and a mission that is critical. Pockets of really smart people. Nice office and location. Very good amenities such as gym and cafe.
Cons
Slow decision making and lack of clarity. Mediocrity is a common trait and too often allowed to persist. Management is often incoherent.