Apply to NASS if you want to see the academy and experience the cool town of Annapolis, but I always warn that the seminar is just a camp that bears no resemblance to the actual life of a midshipman. It’s a great opportunity to roam the post, get your questions answered by actual mids, and complete a CFA (if you choose).
Also, because the academy camps are pay-to-play and there are not enough spaces for every applicant, they cannot be considered part of the admissions rubric at any academy as the appointment process is mandated to be equally open to all applicants. So, there are no admission points or boost for attending.
Our son did not attend these camps. During his application process, both his FFR (Army Field Force Rep) and his BGO (Navy Blue and Gold Officer) told him that he could apply to them if he wanted to play soldier/sailor for a week and wanted to check out the posts, but he might not get a slot as he was not the profile the camps target, and because he had made it abundantly clear that service academies were his first choice for his college experience, the camps weren’t going to be particularly informative for him as none of the summer programs reflect the life of an actual cadet or midshipmen in the least (and now that he has graduated from USMA, he can confidently concur with that assessment). They are marketing outreach tools targeted to strong candidates who may not consider an academy or are on the fence about them, and they are also used to increase the pool of candidates for selection from under-represented groups. Also, they are designed to highlight the “cool” and not scare off participants. (If they actually reflected the life of a cadet or midshipman, no one would apply. 
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