There is definitely a lot of confusion and 'legacy' approach going round, and Poser documentation sucks in this respect. If the approach to shaders was changed between versions, I would expect clear guidance in the documents how to render 'old style' and what to do to old content items to make it look good in 'new style' renders. 

On the other hand, let's not forget that Poser is not a scientific tool, but a product intended to make some form of art, and so in most cases for fun. Too much emphasis on the math side would take away the fun for many of us.

Nevertheless, it would be good to have some good examples of images of different styles, with all aspects, light, shader used, and all render settings included and explained, and how modified settings change the result.