I had written that the Swiss stops felt better than the Zipp's. After some additional testing I am going to stand by what I said about feel but add something new about safety. If you are riding any brand of carbon clinchers safety should be more of a concern than feel. One of the test engineers at Zipp "Jason Fowler" took the time to educate me on carbon rim braking and how Zipp had tested and developed the carbon pad they are recommending for the 404.
Bottom line - The Zipp cork brake pads might not feel as good as the Yellow Swiss Stops but they generate less heat and are a safer product.
Here is what Jason said
All the available Zipp pads listed below: Since this article was written Zipp have released the new Platinum pad. Not yet tested but they promise to be another step in the right direction from the guys at Zipp who take cabron braking and pads very seriously.