Pink, my son was a NAPS 07 grad, now a 2/C @ USNA, and what struck me about the NAPS classmates I met was how diverse their qualifications were. It's tough to generalize because among the 250-300 students, you find a mix of ... everything. My son was one of the ones w/ a 4.0 (w/ honors and AP classes) plus great leadership but only mid-to-high 500 SATs. There were also NAPSters w/ great SATs or ACTs, not-great grades. And great GPAs and scores but not ready for USNA in terms of fitness. And recruited athletes and priors who showed great promise in performance/leadership, but in need of academic refreshers.
You've read all this before, I'm sure. Really, you just can't generalize, except to say that they all had something the Academy wanted, and they wanted to be there so much they were willing to put in an extra year (which must seem like a lifetime when you're 18).
Oh, and the other thing they had in common was being the roommates everyone wanted as plebes.
Good luck!