His unique and original style of drumming has influenced an emerging generation of drummers. More than a few critics have called his style "schizophrenic", and this has attracted a significant portion of SOAD's audience, and it's generally agreed that his talent is a large part of SOAD's appeal.
John's facial expressions are famous for being constantly foreboding and angry-looking, which together with his usual smart dress sense, make him look like a Russian Mafia member. Lead singer Serj Tankian was quoted in Kerrang magazine as always trying to make John crack a smile on stage, to which John replied that he had to make an extreme effort to keep a straight face and not get put off beat. Which is sometimes not believed due to the fact that John is very rhythmically sound when it comes to his drum beats. He is known throughout the metal scene for his high-hat to snare combo, which can be heard in such songs as Deer Dance on Toxicity I-E-A-I-A-I-O on Steal This Album! and Question! on Mezmerize