Pros
Interesting projects, assuming you like defense stuff. Small business environment where everybody knows your name. Free coffee. Free cake/pizza once per month.
Cons
Company tolerates caustic behavior from low-level managers. Extremely high turnover - half the people I worked with there got burned out and quit within a 2-3 year window. Consistently low-ball applicants on salary offers. Opportunity for advancement/promotion sucks because the company has a "flat structure." Vesting schedule for their ESOP and 401k matching is extremely slow, so if you get burned out before 3 years and quit they can effectively keep part of your salary. If you are vested, their procedure for distributing ESOP funds is a pain. HR is unhelpful. Performance reviews are extremely subjective and give caustic managers the leeway to play favorites.