I don't know about Sum 41 being METAL, but I did see them do a version of Dio's "Holy Diver" on MTV or MTV2 (I can't remember). Also, they have one video where they do a "SPINAL TAP" like song at the end, I think its called "PAIN FOR PLEASURE". I think they are better and more talented than Linkin Park or Limp Bizkit. Just my 2 cents.