Tima, my question was in the context of the conversation. Different materials get chosen for different strategies. I am a fan of shun mook but not of quadraspire or other wooden racks. There are many shun mook fans who tried ebony alternates and failed.
The Yamamura owner told me that there were 4 speakers made by Yamamura and he liked the 4th. Material was the same. What yamamura was doing was fine tuning his design, the size of the speaker etc. This is always the case, irrespective of the material. What designers who succeed have done well is fine tune their design, whatever the material of the speaker. All materials have a voicing. There are so many ways to make a speaker sound bad (overall design, crossover, drivers), that it is impossible for someone to say wood sounds better than composite, same is claiming epoxy resin as the magic material because Rockport Arrakis uses it. There is just no way someone can establish that. Rockport can do it for their rockport speaker that's all.
There are some things in audio that are difficult to confirm. Confirming speaker material is probably the toughest. Anyone can list the speakers they like and the ones they dislike, the least pattern you will find is with speaker material. It is also the toughest to practically research, because you cannot replace the material of a speaker with another and see if like changes to dislike or vice versa.
The other thing in audio difficult to do is making statements on DDs vs idlers vs belts and generalizing them. I summarized why I think this is difficult to do here
https://www.whatsbestforum.com/threads/belt-drive-turntable-sucks-what-do-u-thk.32980/post-721032 .