Vantaggi
Stability, benefits, and salary are all very nice. It's a great first job for any engineer. Rotational assignments are a possibility when starting as well. There are a myriad of different job types, job locations, and people that you will work with at NG. Chances are, you'll find your niche while working there. The work environment is minimally stressful as well. Defense schedules are generally more drawn out and forgiving then private industry engineering. The work/life balance is quality as well as NG allows for a 9/80 schedule and very flexible work hours (depending on your immediate manager). Benefits, vacation, etc. are all comparable to other defense contractors.
Svantaggi
Morally, you are part of the enormous war-making machine that is the defense industry. Also, at a company the size of NG, feeling like an employee number is typical.