Pros
Total compensation is much more than is deserved. Getting promoted and getting at the top of your field is actually pretty easy because the competition is so low. If you are an intellectually stimulating, self motivated go getter, you may have a difficult time developing relationships with "co-workers". To be honest, not much "co-working" going on. You, the go getter will be doing all the hard work while your cohorts make "appointments" and get "hurt" and use their doctor's notes to sit on the sidelines and watch you sweat. Good luck!
Cons
Almost every aspect of the US Army is bad. The less you work, the more you earn! So if you are looking for a an easy job with no requirement to think or any serious responsibility, join! They want people like that to fill the ranks. Overachievers, I am warning you, it will be hell on earth. Especially if you join as a non-specialized enlisted member.