Does attending a prep school over community college really seem that much better when reapplying?
If you are sponsored by the academy to attend prep - you must go where they tell you to go.
ALL those sponsored by West Point must attend a Military Junior College. USAFA and USNA use a variety of colleges - MJC's, NWP and prep boarding schools. They all have good acceptable programs and the appointment is the candidates to lose. It's win/win.
If you are NOT sponsored:
No. One is not "better" than the other. I just caution kids who are NOT sponsored to fully understand what they are getting into. Eyes need to be wide open here. It's awful to have a kid say they spent a year at a prep school with the hope they would gain an appointment only to find they still don't have an appointment and have wasted a year.
My advice is - if you have a ROTC scholarship, then accept it and go to college for a year. Take the courses advised by admissions and reapply.
If you have been accepted to a 4 year college, then go there; especially if it's a good school.
If you attend a junior college or community college; then look for articulation agreements for credit transfer.
If you think you might benefit from a post grad year - you need help with study skills and SAT scores - then consider that. Realize that it's expensive and there are no guarantees.