I use a Elecom Huge with drag-scrolling enabled (check xinput if you're curious!). For any kind of scrolling I just hold a sidebutton down and roll the ball, it's very handy and feels better then using a wheel, even if imprecise.

For exact scrolling I'll use the scroll wheel or dive for the scrollbar.

What I really want is a toggle bound to a button for enabling/disabling drag scrolling. Most of my flow is keyboard based so being able to toggle that on/off for a dedicated stroller would be great.