Pros
They have a decent benefits package - free health care, life insurance, college, etc. You get 30 days off a year plus holidays. You can control the rate at which you are promoted. They teach you how to be a leader
Cons
That decent benefits package has it's downsides - the free health care is like the worst free inner city clinic you can imagine, the life insurance will only pay out if it has to, you have to wait 3 years for the MGIB/Post 9-11 MGIB before you can use it and Tuition Assistance is likely to go away soon. That 30 days a year of leave and holidays you get off are all given on the basis that it doesn't affect the mission. While you can control the rate at which you get promoted you have to be extremely political and do all the things you are told to do even if they run against your beliefs. They teach you how to be a leader by genuinely showing you how bad leaders can be. The cream doesn't rise to the top. 99% of the time, the people that kiss the right ass rise to the top. Finally, and this is the most important, they own you. They tell you where to be every single day, how to dress, how to cut your hair, how to speak....everything.