Got it - in fact I did read that thread when it started, and it contains a lot of really useful discussion, that I should have looked up before I started this latest thread.
“Why Sharpness” also contains a hummingbird photo processed with and without the new “Diffuse or Sharpen” module that probably says it all much better than I can.
So to change the subject a little, why did I not find that thread? The simple answer is that the pixl.us search function is not sophisticated enough to search for “sharpness” when you ask for “sharpen” or sharpening"
I started to write up a “Tips and Tricks” document about sharpening and contrast as a candidate entry in a new DT “Howto” Wiki. (see this thread).
As soon as I pulled together the material I know about, I realised its a lot harder to get it right. And likely contentious too. But still I think its worth trying as there is so much good information on DT hidden in these pixl.us threads. Information that could be distilled down to usable easily referenced tips and tricks, without losing the arguments and discussion of alternative approaches.
I will keep writing up my tips and tricks docs, and maybe at some point I’ll be confident enough to share them for general use.