Pros
Good life-work balance. Most people are nice to work with. Descent pay for the area
Cons
Have you ever heard of brain drain ... this phenomenon hit defense pretty hard. Nobody wants to work in an industry that is run on 80's business model. Too much bureaucracy, too much red tape, work on your own culture with minimum development from your managers. Promotion is based on how many years you spent with the company versus skill. You feel like a # going to work every day among a sea of other engineers. The management is clueless as to why people are leaving for Silicon Valley and other startup. If you are in this industry for more than 3-4 years, good luck leaving ... your peers who work in commercial/medical world will be running circles around you by then.