Yeah, Mastodon was horrible. It was one, large, loud,annoying noise. I could not hear when they were done. Umm, Dragonforce was pretty good. Not as good as Slipknot or Disturbed, but if you like Dragonforce, you'll be happy with the show, especially when they played their new song. I'm not sure what his name is, but their keyboardist was rockin out big time.
BTW, when Slipknot plays Corey(#8) will tell you a little story about Sid(#0).