Join Date: Feb 2016
Location: Spacecoast Florida
As far as heat shields go, the stock heat shield is three layers of material. The innermost piece is the one that has heat shielding material on it, and does most of the work. The outside layers are mostly to provide a layer of airflow between your leg and the exhaust. As far as I know, the carbon fiber options simply replace the outermost layer (keeping the stock inner pieces), so I don't think it would make that much of a difference.
I did notice a significant difference when I did a full-exhaust replacement. Overall, the bike definitely runs cooler, and the exhaust heat is less in many conditions. I also notice that the bike cools quicker when I shut it off at the end of a ride, indicating that heat is dissipating better.
That said, I live in a warm climate, and when I get in a situation where the bike is running and not moving much, or after riding the bike hard, it is still plenty hot. My other bikes get just as hot temp-wise, but have bodywork and under-bike exhaust to keep the heat away from me.