I noticed quite a difference. I went from a carbon-wrapped aluminum post on my Cannonade Six 6 (aluminum with carbon rear triangle) to the lightest china-made carbon post I could find on eBay. Definitely noticed a smoother ride, but this could be entirely due to the lack of material in the new post... not that I'm riding a noodle, but if I had to guess I'd chalk up the difference to the weight rather than the material.