There's a glitch that lets you boost extremely fast going off of a ramp. That may be it.
http://xboxdvr.com/gamer/BigEvilTurtle/video/13024858
Nah I knew about that, apparently it's slightly faster than the original slide jump boost thing? Who knows. I suppose if it gives you similar momentum, it's better than jumping and potentially putting you in a trickier position.