I saw Dethklok in Berkeley, CA on their first tour. They were not very good that night. The show's creator was singing and playing guitar, and he looked like that show was the last place he wanted to be, even though the venue was packed and there was still a line outside. There was a video of random clips from the show that was playing behind them throughout the set, and it had nothing to do with the music, and was in no way synchronized to the performance. The sound wasn't very good either. It was a massive mudfest, and the only way you could tell what song they were playing was by the vocals, which were half-assed, and the guitar leads, which were played very sloppy. All the members were standing almost completely still too.
Hopefully they got their stuff a little more together for this tour, because they have a good chance to make it something epic.