Good points, and I do use coatings I used them on my RAL Shiny Plastic and RAL Car Paint lines instead of using additive layers for the very reasons you outline.
Actually my very first post to the forums was a question regarding why coatings are not the solution we want them to, here:
http://www.maxwellrender.com/forum/view ... 97&t=34365 so this is a topic I've been thinking about and talking about since the very beginning.
Using a high-frequency bump for roughness introduces poly-faceting in many cases... so it is not the optimal solution. If you care to know, I can give you the full rundown on what I have suggested to others at Next Limit for increasing the utility of Coatings and decreasing the need for "Additive" layer mode (or eliminating it altogether)-- I'm actually probably the most pro-coatings user on these forums, but I'm also realistic about what the current implementation can do.
I'm very far from someone who has "boxed in" thinking on the subject of materials -- for example this recent thread here:
http://www.maxwellrender.com/forum/view ... 74#p353774 I made 4 different looks with the same Arroway textures (2 of which you can download), just to show it can be done with ease. I think you are making assumptions about what I do and why I do it that are unfounded in any facts -- I make great effort to be as thorough as possible when designing materials for others to use.
The wizard materials by comparison of very often a disaster, and most of my RAL lines were created to be a direct alternative/solution to the wizard equivalents.
Best,
Jason.