I was at this show too. I'll agree with people that the Dethklok set was the best thing of the night. Mastodon was good, their encore was great, but it didnt get the crowd going insane like Dethklok did. Seriously, on the opening like 5 beats of the Deththeme, people were moshing, going nuts, freakin out and it didn't stop until the end of the show.
I couldn't make up my mind if it was funny or sad that people were moshing for the Duncan Hills Coffee Jingle.