The main scroll wheel should have two different speed settings: a minimum increment, and the existing scroll speed.

When smooth scrolling is disabled, the minimum increment is FAR too small. It takes 2-3 ratchets to scroll a single line of text. That tiny ratchet increment is the same whether the scroll speed is at 0% or 100%, because that setting only kicks in when the wheel is spun relatively fast. As it currently works, it's unusable for me—I need to enable smooth scrolling (which I don't really want), to get a faster speed on the low end.