What impressed me most was that:
1 - His words came from the heart and the gut
2 - He did not (at least as far as I could tell) have a single note in front of him.
All of the seniors did well speaking, but all except DO had things written out. At this tender age it is usually very hard to get up in front of a crowd that large and speak, let alone come across well. All of them seemed fairly comfortable doing it though, but DO took it to the next level. Don't know how many of you have ever had the chance to stand up in front of a large crowd and speak or present, but it generally takes years of experience to develop a comfort zone like that and come off as well as DO did and again without a single prop. Very smooth.