Here are the examples:
Without motion blur its hard to follow the movement. It looks unnatural.
With (fake) motion blur it looks like a real movement. Its a bit over done to show the effect more clearly.
Of course you have to take care at the speed of the movement. As you can see I peaked the blur at the steepest movement curve. And I chose the leftward parameter at max. level.
And one last thing: This last preset with the separate 4 directions is nearly impossible to preview but for some reason it renders more quickly than expected.
