OKAY, I think I can clear some of this up.
Taking a look at the PAL xbox version right now, in the flesh, I can confirm that the "glowy flashy retard after-effects" sparks are REALLY in there. it really depends upon which mode you seem to be playing. and yes, SPEED MAKES A HUGE DIFFERENCE. In Takedown mode, the effects seem to get way flashier--but the pics making the round right now are ridiculous. They don't look like that weak-ass straw

--you need quite a bit of momentum going to produce a huge shower of sparks, but they are there. Also, the number of sparks is just insane.
Now shut the flying hell up, will ya?