I can't help but put input on this one. Back when I was applying, the same was true that you typically had to wait, wait and wait some more before you hear. Our DS had his app in full by the end of August. What is the benefit here? Mainly that you don't have to worry about all the work required to complete an application while going to school, playing sports, being heavily involved in ECA's, etc. The benefit is NOT necessarily that you will get looked at early (though it is possible to get looked at early). I have often pondered why the process takes so long and demands patience of the applicants, is actually a character building tool that is VERY useful later in life in the fleet. Like several have said, we think each of our kids are the best and the brightest. But the issue is there are hairs being split since most all of the applicants are the best and brightest. So when our DS/DD is given a whole candidate score, they may be ranked 700 out of 1500, when we all along have been used to them being in the top 10 (or at least top 10%) of whatever it is they do. So getting your app in early doesn't mean in any way that your "ranking" is improved. Rolling admissions is that they are reviewing the slates on a weekly basis and awarding appointments from various regions in chunks. Not in ANY given order that we as observers think makes sense.
And lastly, I will echo loudly what NavyHoops said. This is not about getting the best scholarship offer, the quickest offer, or anything like that. It is about the lifestyle of leadership and hard work followed by military service and if this is for you. Everything else can wait if it is in fact what you want to do. Because what she said is so very true, if serving is not a priority, it will be a miserable experience.