I used to ride a carbon post in a steel frame, and it definitely took the edge off the road buzz. Then I switched to a carbon frame and transferred all the components, including the carbon post (same size seat tube). The post kept slipping, so I kept tightening the binder, and eventually it damaged the post. On to the next carbon post (one made by the manufacturer of my frame). Gust of wind blows my bike over and the seatpost shatters at the saddle clamp. No more carbon posts for me, I've got a nice aluminum Thomson post now, and it doesn't weigh anymore than the last carbon post. Half the price too. With a carbon frame I've noticed no difference in ride between a carbon and aluminum post.