Personally, I think it's harder to go from enlisted to the academy. 1st: Enlisted is NOT a cakewalk. It's a full time job. A job that can be 10-12 hours a day depending on your type of job. Trying to stay up on taking some off duty college classes to stay up on your math and science skills is almost impossible. (Not impossible; many enlisted get their BS and MA/MBA degrees). Just very difficult. Then there's the fact that it's a lot less slots.
Personally, if it was me or my son/daughter; I would recommend that you stay in the "Academic Mode" of thinking. If the academy doesn't accept you the first year; enroll in a good school at home. E.g. State, or University of .... If you can't afford it, than go into a community college to keep your skills up while you're re-applying the next year. At the same time as applying for the academy, you SHOULD BE APPLYING FOR AFROTC. If you get AFROTC and not the academy, you get your college, and you can still reapply to the academy the next year. (Personally, if I had finished 2 years of college, I probably wouldn't apply again to the academy; even though there are those that apply to the academy and they've come close to finishing their B.S. from a civilian school).
Anyway; enlist to academy is definitely possible. I personally think it's the hardest of all methods. Between your Basic Training, then months of technical school, NO SOCIAL RULES AT ALL!!!! I.e. You aren't a student. You're in the military. You are free to come and go all you want as long as you're at work. There's no curfews or anything else. Many 18-22 year old airmen like the freedom. Anyway; just my opinion. I wouldn't do it.