I totally disagree with those stating that the only difference is in price/weight/brittleness. Across the board in my experience, the higher end carbon bikes, are generally laid up differently, and the frame is able to be "tuned" creating a lively, responsive feel that the lower end carbon versions of the same frame are lacking. It's really pretty obvious if you have access to, and ride many road bikes of various brands.
I think maybe those that claim the lower grade carbon frames are the same except for weight and price probably own the lower grade carbon version of the brand they are riding, and are making themselves feel better about it. There is a difference, and it's not marketing.
we're not talking about a canyon cf slx vs a btwin 540.
we're talking about bikes in same family, range, design, platform, model, whathaveyou...
they can be rolling off literally the same mold, just with a different cf sheet or or there.
sure frames make a difference, but the first order determinant is the overall design - sections, profiles, geometry.
that they slap a t1000 square instead of a t800 square at the bb junction for me probably falls under 3rd order.
from a sellers point of view this is the greatest thing going. make a design (the time consuming spart), order some molds (the $ part).... and heres the easy part: change the layup schedule minimally, call it OCLVxx or xxR or HMx and bam, you got 3/4/5 different "models" targeting every stratification of the target market.
i'd love it if the manufacturers publish deflection tests on the bikes for fitness. or fit some accelerometers and test their comfort. cant cost more than wind-tunnel time, if you ask me. we know from countless studies in countless fields about psychosomatic effects and how our expectations heavily
color our perception. for the exact same base frame, lets see matter of factly how hi-mod is truly different from nor-mod......