Pros
The greatest reason to work for the US Army is the honor that comes with knowing you make a difference in defining America. One is never faced with the dilemma of doing meaningless work. The friendship and camaraderie is unparalleled with any other job field in the world. The US Army is also one of the only jobs in the world where someone is paid to ensure your well being, and is assessed based on your well being. They are also one of the only employers that take on full responsibility for lodging, food and medical care for you and each one of your dependents.
Cons
You are required to spend time in foreign lands in dangerous situations, far away from everything you consider to be normal, for extended periods of time. Long hours are compensated for, but the army has no concept of overtime; work is done to standard, not to time. Soldiers live, and die, in harms' way. You will face loss, hardship and deprivation. There is a strong possibility that you will be more knowledgeable than your supervisor, but powerless to change the balance of power. A lot of the standardization and uniformity in the army does not make sense to free thinkers