I was actually trying to dig up some DDR videos for you guys. These aren't too great, but they might be worth a look:
http://aaroninjapan.com/ddrvideos.html
Scroll down and look at any video with the word MAX in it. The MAX series is the fastest in DDR; the slowest goes at 300 BPM, the fastest at 333. I can barely beat MAX300 myself. These guys hit every step on every one...