I too bought the $6 one from buynshop and I have no problem with it on Step Mania 3.0 But on CVS it takes a while for the game to recognize that you hit the button. I don't know if this is common or not. But you can still use 3.0 Have fun!
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Call it DDR! Call it ITG! Either way, it still taste like chicken.
Konami created it (DDR), RoXoR perfected it (ITG), and we should all respect them equally.