I went to this last year (of course it was easy for me because I live in Denver). It was a great event with a lot of useful information. It is a great opportunity to meet the people who will be making the acceptance decisions and hopefully make a positive impression. Foodzie, one of the companies that made the cut last year, did a nice job of this; they gave everyone a piece of candy packaged with their logo.
If you have a team together already and are good at meet-and-greets, I say fly in. If you're a solo founder and/or not that interested in meeting, pitching, and networking, it may not be worth the time and expense.