Pros
Fixed schedule due to how government contracting works. All hours are accounted for, which means overtime has to be approved on a contract. 9/80 schedule can be a benefit if people are used to working long hours a day. Opportunities to work on different technologies from a variety of contract wins. Good 401k match. Vacation times are great for tenured employees.
Cons
Mobility between projects is both a boon and a bane. Talentless employees are often retained due to government mandates on minority/gender quotas. Employees are mired in an attitude of apathy being caught in an upper management political machine where middle managers attempt to carve out their own fiefdoms. As with all government contractors, waste is rampant. Success of projects are dictated by how much money the company can bilk out of taxpayers. Innovation is scarce; security dictates that any open source related technologies must go through a tedious process of scrutiny before inclusion in any type of classified environment. Serious ra-ra! attitude in support of the "warfighter" in an attempt to justify poor practices. Health benefits are terrible and vacation time for new employees is abysmal. Pay scales are below industry standards. Review practices are archaic with a rating system pitting employee against employee where upper management "ranks" each person with quotas for the amount of exceptional to abysmal ratings awarded.