I attended every demo day session (and the practice sessions before demo day) for about 2 years* and the real difference between the audiences depended on time

I attended every demo day session (and the practice sessions before demo day) for about 2 years* and the real difference between the audiences depended on time of day. I think a "good" presentation had a lot of people writing things down, vs BlackBerry / iPhone reading. Also, back when there were more sessions and they happened at YC HQ, the time of day played a big difference. The later sessions (I think they started at 4?) had people actually laughing at jokes, whereas the earlier sessions some of the exact same jokes, seemingly delivered the exact same way missed really badly. (I remember people actually cheering for Hipmunk's presentation. It felt like a home run.) I don't know what it meant for follow up, but two notable presentations at least generated some memorable notes that I spied over people's shoulders. Jason Shen from Ridejoy did a cartwheel on the way in (he's a former collegiate gymnast) and I saw a lot of people drawing stick figures cartwheeling. Also, during SiftScience's presentation, one of the founders punctuated his presentation by saying something to the effect of "We're going to stop people from fucking with our customers." A lot of people wrote down "fuck" next to their name :) I don't know what happened to most of the companies post demo day with their applicable raises. *: I did behind the scenes work with YC as the audio / video guy for a bit, before they went to the CH museum.