Ventajas
had a good pension still have a cash value pension and contribute a lot of money to the plan. My first ten years at the company were great. Their flexible work schedule was great as well. they refurbished most of the building so the building became a functional work area. I got laid off but I worked there 2o years which was ten more than I thought id survive so from a work and benefits Standpoint I can't complain. However there are aspects to this type of employments that can be less than pleasant. moreso than non defense employment. Its not for everyone.
Desventajas
have become more and more politically leaning especially with their close ties to the current administration. Became harder to just walk into the building. No windows. but again for a large part of my career it wasn't bad working there.