Hello Blub!
I'm currently an MS4 and am an Army National Guard soldier(not air guard). I know that some information overlaps so I will try to be helpful. also, if you would like, I have a classmate who is a proud air guard soldier that would respond to any questions you may have. Briefly, I've been in for 10 years, joined when I was 17 and at 27, am halfway to retirement. During school I was required to drill, this can be frustrating during didactics bc i worried about studying and during clinicals. However, with some preplanning my grades were never affected and I never had problems coordinating days with attendings/hospitals. Plus a typical drill weekend will provide you a $400 paycheck (helpful during med school). I only have experience in AZ/OR guard, but both have been very accommodating to my schedule requests. You will have to attend a 3.5 week training within two years of joining. I completed this my first summer of med school. I've done multiple enlisted trainings and this training is so easy, I was sorta embarrassed for medical officers but I enjoyed it. Benefits during med school: $4500/yr tuition assistance and monthly GI bill (I think like $150). ALso, eligible for National Guard health insurance ($46/person, $150/family) that is equivalent to your school insurance, this saved me a few thousand dollars. They also reimbursed my boards (a few thousand).
As you enter residency, there is a flex training program for residents that is dependent on the State Surgeon of your state. The rules require drilling like 4 times per year. CME can be considered army time. You are also eligible for STRAP at $2000/month but this tacks on 1 year of service for every 6 months of benefits. Now after residency, you will start receiving $40,000/yr of loan repayment up to $240,000.
I've honestly enjoyed my service in the National Guard. I'm not financially stressed like multiple classmates and it added a lot of leadership experience. I feel like it diversifies me since I'm a 5'3" girl that knows what an M16A2 is and how to low crawl. I get to serve in the military while not being forced to live somewhere; the Army follows me, I don't follow the Army. Here are the cons: time, weekends. Deployment after residency (3 months on the sand) is a major possibility.
Please let me know if you have any clarification questions.