Pros
Decent pay, great work-life balance, generally good colleagues, and a purpose-driven life. The training and travel opportunities are often unique and interesting, as well. Good ideas and good work are rewarded and recognized - if you know how to work your way through the politics and bureaucracy. If you have a terrible boss or work with slow or generally awful people, there is the great comfort that they'll likely transfer to another job in a faraway location within a few months.
Cons
Culture can be very rigid, promotion potential as a civilian is limited, and the bureaucracy can be infuriating. Working for the Navy at the Pentagon can be particularly frustrating, especially when faced with mid-level officers and civilians that respect rank more than merit.