bulgie Mark,
Altogether a very interesting and informed perspective, and I agree that when it comes down to being strictly scientific about the matter there probably isn't a way to prove the issue of efficiency vs. stiffness, because the variables are far too considerable to rein in for any one rider, not to mention any day of the year or road out in the world.
However, for as much as you might assume I am not really "interested in the other side" of the story, the very pessimistic view you relate of the modern bicycle manufacturing industry and related invention and promotion of new technology seems quite heavy-handed. Do you think tens of thousands of professionals go through their lives studying, designing and fabricating bicycles and advancing related materials like carbon fiber simply because it seems like it'll make them a buck more than the older stuff and that they're only trying to maintain consumer demand? This is a rather petty outlook on things, especially when for fifty years during the post-war period the bicycle industry was as easy as stamping out slightly modified versions of the same old components and changing paint and chrome schemes and tube sets now and then on the frames. A lot of hard and meticulous efforts go into fabricating all of the shapes and dimensions of carbon fiber bicycle frames, and the tolerances for every component these days are unbelievable. Component and frame advancements over the past two decades has been on par with almost the entire period since the derailleur and classic racing geometry became commonplace. It takes
many more hours or a
far greater investment in industrial processes to fabricate modern carbon bicycle frames than it does to weld or braze together a few tubes, and the consistent variety and evolution of frame dimensions via trial-and-error studies and material developments make the modern bicycle industry rather marvelous, fueled by many passionate people. To dismiss all of those labors as being done merely in order to sell some stuff is pretty much to admit ignorance, complete bias or total disregard.
Really sorry to digress here. If you want to continue the conversation, you're welcome to PM me, Mark.
-Gregory