question about headsets
 

I was looking through Cannondale's road bike models and noticed that some of their new 03' models use a Ritchey Si headset instead of the customary Campy hiddenset

I don't know too much about bicycle mechanics but I'm wondering if anyone could point out the differences between the two if any? I tried doing some searches but I came up with nil :/

Richey is likely just pedaling their own version and Cdale,makes more money.