I live in Southern California so I don't get much of a chance to test braking in wet conditions but I do a lot of regular rides that include 5-10+ minute descents with lots of hairpin turns that require good consistent feedback and excellent modulation.

The descents are extreme enough where I've melted a half dozen carbon clinchers from various manufacturers, but my Zipps have held up great!

I've had the chance to ride both the cork and the platinum pads on a set of Zipp 404 Firecrest Carbon Clinchers and a set of the platinum pads on the 303s. I can say in that my opinion, the platinum pads performed much more consistently and predictably.