Additional Motion Blur Settings?
Apologies if this has been requested, however I couldn't find this.
My suggestion is to enhance the current Motion Blur feature within the 'Layer Properties' to give more samples/scale/frames/blur amount to the layer or effect.
E.g. I have been playing with the Motion Blur with the Particle Simulator and I would like it to blur more as you can still joins in the effect and it would like it to be smoother.