Pros
Stability - one review I read said "once you are in, you're in." Good benefits package. Focus on work life balance with flex time, telecommute, etc. Caring management and strong sense of community. Plenty of support and time for learning. Good educational assistance program. Many lifers here as it is an easy place to put in a 30-40 year career.
Cons
Not the most challenging place to work. Plenty of bureaucracy. Similar to working in a federal government organization. Still a sense of hierarchy and "putting in your service" in order to advance. Main business is weaponry - if that doesn't sit well with you it probably isn't a good fit. Lots of ex-military employees. Stability and predictability is paramount - ingenuity, innovation and risk taking are embraced in words but not in practice.