I wonder too. The fully floating part is likely not the only reason though. As for pad drag (the apples to oranges video you posted earlier), that's a definite benefit, but I'd be extremely surprised to going from semi to full floating, with no other changes, will make your wheel spin 100% free like his. I'll be removing my anti squeal clips from my pads before this season to decrease pad drag. I'd imagine that him wiggling is rotors before spinning the wheel would have widened the pads slightly, helping his demonstration. Call me a skeptic, but there has to be something else going on there to decrease the drag that much. A friend of mine had an ex-CSBK Pro 600 bike with fully floating rotors and the front wheel didn't spin as easy as in that video.