I'm working with a LT COL from the Army and he loves his prior experience as a general ophthalmologist for the Army. He did over 900 cataract surgeries, plastics, glaucoma, retina, etc... He's now training to be a retina specialist.
One of the faculty at Iowa served 23 years in the Navy. He enjoyed working for the Navy as a GMO and ophthalmologist.
I had prior service in the Army Medical Department, and I can't wait to go back on active duty as a physician. To be honest, I've met some docs in the military who couldn't wait to become civilians again, I've seen military docs who couldn't imagine doing anything else, and I've seen docs who left the service, hated the civilian side and re-entered the military. It probably all depends on the individual.