Crazy Legging (movement problems)

There used to be this thing called "crazy legging". Some called it "tap dancing". Basically you'd hold either A or D, and while still holding one of those, you'd rapidly tap W to make your character tap dance. It was pretty good for rush knifing. Lately I try doing it, and I can't hear the noise. So I watch some replays of myself doing it, and instead of tap dancing, my character is TIP-TOEING!! WHY?? Is this just a replay glitch or is the movement in CF changed forever?

ALSO, while watching people play in 3rd person view, they're all jittery. Is this also a glitch in some new type of movement system added by z8 in the latest patch? Someone's gotta fix this.

Any ideas/thoughts?