Hey -- I really think for me, it came down to fit. I have had two friends go through the AIE program, so I've seen exactly what it entails, and knew exactly how that program would apply to what I'm currently doing. I used most of my SOP to really articulate my need to be in this program at this time in my life, why AIE, and how I planned to take advantage of the entrepreneurial spirit of the program. My resume backed up everything that I had to say in my SOP, but I did not re-state anything on my resume in my SOP, if you catch my drift.
My GRE was literally on the mark of what they consider "average" on their website, my GPA is below average, and I went to a no-name undergraduate program in the South. I applied for the part-time track and intend to continue to work in my current role for the duration of the program. I currently work in an executive role in the arts, have 3 years of full-time experience, and have a very long track record of extensive volunteer work specifically in my field and in the interests I outlined in my SOP. So essentially, what I think made me a successful applicant was: 1) 100% authenticity and self-awareness, acknowledging my mistakes, what I lack, and what I need to grow, 2) tremendous consistency in what I stated as my goals as backed up by my career and volunteer work, and 3) clearly articulating that I knew exactly how the program was going to assist me in getting to where I needed to be (and where that is!). I've applied to quite a few other master's programs in the past couple of years, but I often found myself trying to prove to the admissions committee why I was a good fit for their program: all of those attempts ended in rejection. I finally realized that I needed to be so much more honest (Veritas!!) about what I needed, what I lacked, and how I was aware of my deficiencies. That's what grad school is about: growth.
I truly, truly believe that admissions at HGSE are holistic, and they are looking to admit individuals that need to be at HGSE, and not TC, Penn, or Stanford GSE. It's a super unique program, and using every single inch of your application to show why HGSE is the only logical place for you is key. Best of luck to you, and honestly--if you end up at HGSE during a time in which you can actually live on/near campus, you are going to walk away with the better deal! I grew up in the shadow of Harvard, just a short drive away, and I have been searching for every excuse in the world to move back "home"! So sad that this won't be that moment for me.
P.S. The 2021 master's redesign in still up in the air. I have seen many posts on here outlining that the 2021 admits wont have the same options as previous tracks, but from every conversation that I have had with HGSE faculty, there is absolutely no finalized plan to do away with the 12 tracks in the fall of 2021. The redesign might wait until 2022, only time will tell. So AIE just might be on the menu for another year, who knows.