Action starts at 0:50 or so. Shit's crazy.
ANYWAYS. I used to do PIU because that's all there was at the small arcade I had, then I found out DDR's more popular and a lot more widely available (I haven't seen a PIU machine around here in years, last I saw was at the daytona speedway in Florida).
So I'm considering getting either two soft mats (one DDR and one PIU), or one of those 3x3 mats (both control sets fit, more or less), assuming the place I move into has a downstairs I can use. I had PIU for the PS2, but the adapter I got to use the controller on the PC didn't work with it for some reason (works fine with official PS2 controllers on PCSX2 though) so I still haven't gotten to do it.
Happy that with Stepmania I can get all sorts of western songs, being limited to 90% K-pop and K b-songs is annoying.