Pros
Interesting work, great co-workers, leadership that cares, outstanding benefits. This was honestly one of the best places I've worked for from a culture, benefits, and support perspective. Unlike most other government contractors, you are hired to the company, vice just to a contract. This means that if the contract is lost, you still have a job. In the time I was there, I saw only 1 person that had to be let go, and that was after months of trying to find alternate work. Benefits (medical, retirement, vacation) are the best in the business and paid (during my employment) 100% by the company. The company encourages you to get certifications and will reimburse you for it.
Cons
Pay, work can get repetitive, small company troubles. The downside to company-paid benefits is lower salaries all around, but they are upfront about this. Opportunities to move up within the company are few and far between, as with most small businesses. However, there are lots of opportunities to move within the company and try different projects.