Pros
Job security is really high, work is important to national security, have nearly every type of job so there's plenty of opportunity to move around if your interests change.
Cons
Grossly inefficient; there is minimal incentive to invest in efficiency because they charge the government by the hour for both hourly and salary positions. Employees find this frustrating because they know of ways to do their jobs better or more efficient but are told there is no funding or willingness to make that change. Knowing that you are working with inferior tools, or using an inefficient process has a negative effect on motivation. Most employees feel like they are 'just a number' that the company doesn't care about them. This is because of limited investment in their development and providing inferior tools to accomplish their jobs. Turnover is very high, it is frustrating to see co-workers leave the company and typically those leaving are the most talented. The company seems unwilling to keep top talent, which further sends the message that performance is not a priority. The company makes most of its money from construction, engineering is often an afterthought.