Pros
There's a wide variety of work available with different customers across the military and intelligence communities, plus a smattering of commercial client work. GDAIS does offer tuition reimbursement programs. There are also some great people working at GDAIS at all levels of employment and across the business.
Cons
GDAIS keeps cutting benefits to "remain competitive" within the industry. Yes, some of the other big defense contractors are, too, but GDAIS doesn't seem to want to be a leader except when it comes to eliminating benefits. Since I started there several years ago, we've lost a week of vacation time total (most recently losing 2 more days for 2012), lost significant 401(k) match options, have seen cutbacks in meaningful professional development & training (e.g. we're pushed strongly toward CBT), have been pushed toward high-deductible health plans (employee pushback has at least allowed us to keep the option of a PPO insurance option), etc. GDAIS is coming across as really nickel-and-diming on overhead expenses, too.