Pros
Great people and interesting projects. Easy to take ownership of something and excel at it. Great work/life balance - at the end of the day you're done and there is no after-hours expectation. 40 hr/week is really that.
Cons
Low raises each year and poor recognition of achievement. Each year, most people get about 2 - 3% raise, never anything higher, but sometimes lower. One year (during military funding sequester), there was a company-wide mandate that the current year would see 0 raises for all employees. I saw several top-notch, extremely bright employees leave because there is little financial incentive for exceptional work. Salaries are about what you'd expect for defense contracted company empoyees, which means they are quite a bit lower than other commercial companies.