Well, Bogan just taught me something new about the istick. If you want to auto-scroll super fast, hold the button until it starts auto-scrolling, then double click and it jumps in .5 increments. Cool!
Once it starts auto-scrolling, press once in the same direction to scroll at .2 increments, press again to scroll at .5 increments, press a 3rd time to stop. When scrolling at .1 or .2, you have to press the opposite direction to stop. At .5, either button will stop.