Pros
Top-notch science. Smart co-workers. Family friendly (flexible hours, kid's holiday party with gifts). Good benefits (no or low health deductibles, 401k match, ESOP through parent company). Accomplishments are acknowledged and highlighted in company meetings. Hybrid of academia and corporate worlds.
Cons
Low pay (10 to 20% below market). Large raises (greater than 3%) only if you threaten to quit with another job offer. Accomplishments are not rewarded (Employees of the year only get a paper certificate in a plastic frame). Company is completely reliant on government contracts (essentially a consulting company) so if there are no new contracts in the pipeline, your job is not secure. They have not been able to replace the "big" contract that is winding down. Therefore there is little to no opportunity for growth and promotions (company isn't growing and upper management rarely turns over). Support departments (HR, Finance, IT) are understaffed, overworked and treated as disposable and easily replaceable (they are seen as overhead or cost centers as opposed to being positioned as a corporate resource). Decision making often based upon cost, not upon needs. Traditional old school inflexible top down corporate management and culture. Little to no formal training available.