Pros
It is a great thing to work for the collective defense of the united states. The military really invests in its people and provides some great benefits and a pretty good salary. I have also been given access to some very interesting problems and some great insight into how decisions are made at the highest levels of government. I have generally been challenged by my leadership and given a chance to make a serious difference. In general, I feel air force supervisors care about the welfare of their people and try to work the system on their subordinates behalf. Moreover, the air force has several 'quality indicators' they use to select for promotion boards (such as top 10% at school, etc) and these are fairly merit-based. You can do some amazing travel and education opportunities. Not working for a profit-based operation is excellent. Some people spend 80-90% of their time learning and personally developing. Regardless of your career-field, you will always be training and getting some great opportunities to personally develop.
Cons
The air force is a large, large organization with a large body of mediocre people. I am proud to defend my country, but I am not proud to be associated with the level of skill that the Air Force hires. As an engineer, the Air Force is also not a place where I will ever rise to the top. The Air Force is an organization built to take care of pilots, particularly fighter pilots, and more in particular fighter pilots from the academy. When it comes to promotions, deployments matter more than job performance. This is not me.