An athlete I coach, Tom Evans was involved in testing the Addidas new trail shoe with a carbon plate. In the lab it was 12% more economical. That’s 12% less oxygen required for the same pace as a non-carbon shoe. Another athlete I coach, Luke Nelson got a pair of C=carbon plate shoes and sees 40 sec/mile improvement on his commute to work.
Technology does make a difference. Noone races on wooden skis any longer. When fiberglass racing XC skis came around in the late 70s it revolutionized the sport. The technique changes to account for the improved economy.
$275 is crazy money but so are $3000 carbon skimo boots and $15k carbon bikes.
Scott