Throttle

[99LRDblaster]

I struggled with twist throttles just riding dirtbikes. I'd be dead if I put one on a quad.

 

[York Racing]

Haha I just like the crisp snap to it when you real that handle back and it gets right up on end through a couple gears. =]

 

[specialized7]

I think its mostly just personal preference.
I personally vote for the thumb.
My buddy has a 400ex and the only thing i noticed is that you cant do a brake torque with the twist because it to hard to hold the front brake at the same time as twisting.
Maybe thats a good thing haha