There's a lot of good and a lot of bad, more so the good experiences but the bad ones can really poison your thoughts.
Pros
Doctrine: Many things are clear cut and not open to ambiguity due to the vast amount of regulations in existence. Promotions: Officer side, there are transparent timelines for promotion at least on the JO side. Leadership: There are amazing people in the Army, leaders I would follow anywhere at any time at a moment's notice. Training: Many opportunities if you take the initiative and follow up on objectives and goals.
Cons
Doctrine: Sometimes it is very inflexible and can make easy things a lot harder and more obtuse. Promotions: It promotes the slacker and the passionate at the same rate, at least for the JO Side. Leadership: Along with the pinnacles of excellence, compassion and brilliance, you may see those with a tin-god complex and the most toxic people you have ever encountered. Training: Some objectives don't make sense. You do it because someone said so, and even after the explanation, it still makes no sense.