I've played on a Cobalt Flux, and even though it's an awesome pad it is STILL not even close to and arcade pad. I don't know why, just that the arrows are a lot lower in the arcade (and theres that silly bar).
Plus the one thing I for some reason cannot transfer from the arcade to home is the difficulty (WHAT IS ARCADE ON??? I think like 6 or so is mine) and the timing. Timing is a LOT more difficult in arcade. If you're gonna play a home version though do yourself a favor and import the DDR Extreme from japan. It is by FAR the best home version ever.