The best thing is the people. My office is very friendly. No one is abused or treated unfairly. Pay is clear and non-negotiated so there is no discrimination there. There is some opportunity to travel and everyone who wants to has been oversees at least once. Work is a strict 40 hours a week and nobody but upper management works any longer than that.
Cons
Some of the work is drudgery and there are a lot of rules that are just "the way we have always done it." Sometimes I lose faith in the "mission." There are a lot of layers of bureaucracy.