Is flying home Thur. night a realistic venture or will I be missing out on the "after party"?
You'll be fine. The day of the event is generally the "main event" but generally the day before and the day after are a lot of fun as well.
Personally, I think it's just fun to interact, in a social environment, other success-driven people. Whatever days you can make it, you'll benefit.
It's not marketing, it's reality. Trust me.