Pros
Free tuition, Veterans benefits. Paid to shoot and blow things up. Health care is free - can be nice to get elective surgery like laser eye surgery.
Cons
Inefficiency is very high. Personnel and finance departments always lose everything, and will instantly charge you if they discover (even erroneously) that you owe the Army money, but it takes months and is like pulling teeth to get money they owe you. Too many layers - have to do the same thing several times for multiple levels of management. Invasive of your personal life. Frequent very short deadlines if upper levels want you to do something, and you must give upper levels a lot of notice if you want to do anything - but they can give you the plan for an extensive training day at 9pm the night before, or change it at the last second.