Pros
There is so much variety of work in the larger company that you're almost assured of finding something good if you look long and hard enough. The sheer breadth of opportunity means that a career can be a rich and varied experience. Also, the work LMC does is often critical in protecting friends and loved ones from harm, which is deeply satisfying. It is easy to feel like your work makes a real difference in the grand scheme of things. In the lower pay grades, employees are given the opportunity to prove themselves in challenging assignments as a matter of course, and the development resources for these employees are numerous. The better managers are constantly engaging employees, looking for feedback, and are genuinely concerned with employees' welfare and workload.
Cons
The biggest downside: Some branch of the U.S. Government is almost always the customer. The U.S. Government can be the most mercurial, bureaucratic, and, yes, downright petulant customer in the world, and often makes unreasonable or impossible demands. This is compounded by management's timidity and lack of support from higher-ups in dealing with these kinds of situations. It's manageable most of the time once accustomed to it, but a prospective employee MUST clearly understand this going in, or he/she will become dissatisfied quickly Recognition is weak. No matter how hard someone works, or how far above and beyond he/she goes, the attitude is often one of, "Well, that's your job." It is not my job to go-go-go to the point of burnout. There is also too much usage of forced distributions for things such as performance appraisals, "merit" raises, and promotions. Worse is the use of "penetration" as a factor in merit raises--if you did well in previous years, you are punished for that success in later years in the form of lower raises once you get above the midpoint of your salary band, even though appraisals are supposed to cover a one-year period. The only way out of the situation is to be promoted, except that promotions, especially in middle and higher levels, are artificially limited (a cost-cutting measure, most likely) regardless of demonstrated ability to work above your grade or penetration in band. At the very least, more transparency in the process is sorely needed It often feels like the company is constantly trying to get new college graduates at the expense of developing its existing workforce (again, they're cheaper to pay even though they're expensive to hire). This is especially true if you are level 3 (Senior) or higher. Due to the bureaucracy of working for such a large company, even the best managers are often powerless to actually do much about concerns raised by employees due to the corporation's stubborn commitment to its way of doing things.