Pros
Working for the US Army will teach you skills that cannot be learned elsewhere - personal skills and traits that will define you as a disciplined, confident individual: attention to detail, perseverance in adversity, ethics, maturity, precision, multitasking, you name it. In addition to learning these skills, you will travel the globe and work with people from many walks of life and career fields. The material benefits packages include full tuition payment, a guaranteed full month of vacation time each year, full health care for yourself and your dependents, and strong retirement plans. Finally, once your time in the military has ended, you will have a competitive hiring edge due to your specialized job skill training and military discipline.
Cons
The US Army is one of the largest organizations in the world. As such, it is rife with political struggle. It can also be extremely demanding physically and mentally. You must maintain high personal fitness levels to keep up with the mission, and your multitasking skills will be tested and likely overloaded if you are underprepared. You can also expect very long hours and high stress. Finally, deployments to combat zones can put your life in danger and separate you from all that is familiar about the United States.