I was brought on board to create these earlier this year (2009) for the release. Although with certain limitations such as not utilizing any plugins and not making the scenes too slow in the viewport and copyright on textures or stock footage, it meant they needed to be more sample files to demonstrate how to create a flow for the set up, rather than a full blown production ready sample, at least in some cases. However I believe that pretty much all of these scene files that ship with max are very informative and useful in day to day production. A lot of the key concepts here are the core elements of what I use in building a lot of my more complex effects and flows. Check out this video just discussing how to use them and make the most of your Particle Flow En devours!