Sometimes the change in speed for one click on the FX wheel is large, as much as 30 fps. Sometimes you want smaller speed jumps. Also settings A-E and 1-5 are two separate scales because of the design of the FX wheel. Monte's wheel, with its 19 steps, is a continuous scale, with nearly twice the increments. While the FX wheel spring carrier adjustment can do all the adjustment necessary, it's slower to move, and not as repeatable as a detent ball. You could Chrony the speed at all 19 steps if you wanted...