As a follow-up to my volumetric fractal noise cloud - vimeo.com/24922196 - I've done a version using Trapcode Particular. This looks very different and gives a good indication of the difference of the two approaches.
Again, the project file is free to download and use under a CC license from the Digital Distortion website:
Loading more stuff…
Hmm…it looks like things are taking a while to load. Try again?