My bf modded our pads the same way last summer, but with third party soft pads. They were awesome at first, but the accuracy isn't too great now. One of our pads is dead (non-DDR related reason), the other is on the fritz, and we got a cheap backup Madcatz that we may be putting into use soon. We play Heavy mode, 7-10 feet, and are really serious players. Aside from the metal pad of the arcade machine, the cobalt flux is the closest you're going to get for the long run. We're going to invest in one because we play almost every day and will continue to do so. We would more than likely spend that much at the arcade this summer (let alone what we've already spent).
However this option isn't for anyone. Like I originally said, you really gotta be into this game to shell out those bucks. If you're a passive player, go for the cheap soft pads and "mod" them.