+1 for spline editing option for automation and controller data.
To see how fast and flexible this type of editing can be, see Cubase’s own Audio/Process/Envelope function (and/or the Fade In/Out functions).
Real World Application…imaging trying to quickly audition the sound of a “fade out” of controller date as a concave, convex or linear curve shape. With splines it takes one click+drag. With points you have to manually redraw the curve every time while trying to keep the start and ends points of the curve from being accidentally shifted. Not a great workflow!
Check out an FL Studio demo to see spline controller/automation editing in action.