I've never been an Air Force nurse, so I don't have first-hand knowledge, but my sister was an Air Force physician, so I have seen some aspects of having a healthcare career in the military.
She went to med school on an AF scholarship
so that she would not be in massive debt upon graduation. She received full tuition, book money and fees, as well as a small living stipend in exchange for a 4-year payback period. The AF chose her specialty for her, and assigned her to a residency program. Her 3 years of residency did not count toward her payback time, as it was still considered education.
She was assigned to an AFB stateside to begin her payback, and would have remained there for her full 4 years, had she not been deployed overseas to a war zone to provide emergency care to a multi-national peacekeeping force. Most of her patients were not American, and she was faced with a huge language barrier in providing care to them. Her husband and children could not accompany her overseas.
She was fortunate that her deployment only lasted 6 months. When she returned to the States, she sought out a civilian position so that she would not have to face future deployments to locations where her family could not accompany her.
When her payback time was completed, she went into civilian practice, which was a huge adjustment, as she had never had to deal with insurance companies before. She found the quality of medical practice to be far superior in the military than in civilian practice.
I would strongly caution you to find out (and get promises in writing) whether or not you will be allowed to choose your own specialty. Good luck!