Breathegood

I say it depends upon the frame geometry more than anything. I have a 1996 aluminum Cannondale that was downright abusive until I swapped to a carbon post. The carbon post upgraded it to only borderline abusive. Swapping to carbon handlebars made a much bigger improvement in comfort.

I have since used the same post on a couple other bikes, one an aluminum hybrid, and the other a carbon-tubed/aluminum-lugged mtb circa 1991. The post made little difference in the ride of the hybrid and even less on the mtb.