My DS was put on a waiting list when he originally applied for the USCGA, probably because his ACT/SAT scores weren't stellar....actually we laugh now since they were at the minimum. Everything else was pretty good, 4.0 unweighted GPA, Class officer, NHS President, Captain of a Varsity Team...yatta, yatta, yatta. He decided to go to Embry-Riddle for Aeronautical Engineering, and then reapplied. After a year at E-R, on a Varsity Sports Team, with a 3.75 GPA, he was accepted on the 2nd try. He had letters from all his Prof's (Calc, Physics, English, and History) on his application. Now he's a 2nd Class Electrical engineering major, top 1/3 of his class.
There are a lot of cadets that self-prepped at civilian schools, some reapply 2 and 3 times before being accepted. I actually think it turns out better than cadets that came right from High School. You have a year to mature, and learn to live on your own, not in a military environment. When you are not required to get up at 6am, but you do on your own, everyday, that shows a different maturity, one you may not learn at MMI.
BTW.....He says that E-R had better professors, and some classes were more difficult.