I also replaced my dura-ace (9 speed groupo right after 9 speed was introduced) pads with Koolstop. The Koolstop performed much better. However I recently got a new bike with 10 speed Dura Ace. The brakes are every bit as good as my 9 speed with Koolstop. I know Shimano supposively made improvements with the brakes on the 10 speed groupo but the Smimano pads definately are improved. The rubber compound is softer and more sticky feeling as well.