Hm, afaik I'm the only one who used it (and started to do it just few days ago when I had to fight a gunboat with slowly turning cruiser turrets on the Order char, it just didn't come to my mind before), and as far as I noticed my speed wasn't higher then the moment before I bounced, it was actually lower. (Since I initiate EK before hitting the asteroid, not like with the ship ramming when you initiate EK during the ram)
P.S. Launched the game, rechecked it. Bounce speed is lower then the initial one. And it's mainly being used not to get away from those who's following you, but to quickly change direction of your movement to evade SNAC (which kinda violates the law of physics in FL Disco universe too, but is required for balance :) )
Anyway, it's not the place to discuss that, I think. And thanks for the nice pewpew there.