Arrh, it all comes back now. I remember reading about the Dominator EVO speedo's, I'm not sure where I read it but I remember it saying that the ESC had a special system, so it had a drive frequency say 2 kHz - 10 kHz and the ESC ran on a low frequency under acceleration, but the ESC frequency changed depending how much throttle input there was, so you got the best of both worlds, a low frequency for good punch, and a higher frequency for good top end.
I dont remember where I read it, But I'm pretty sure it was a review by one of the Nosram drivers.