The US Centurion doesn't offer nearly as many insurance benefits. Specifically, none of the benefits related to travel not charged to the card (unless they've switched policies and have yet to inform cardmembers).

It does offer gold status with Continental, US Air & Delta (previously also Elite 1 with TWA) and premier status with Hyatt (Diamond) and Intercontinental. Most other benefits are the same as those offered with US AMEX Platinum, including access to US lounges of CO & NW, comp tickets for international 1st class or bus class flights originating from the US, FHRS, etc - with fairly minor enhancements to the insurance programs.

ANY add'l card (green, gold, platinum, centurion) is charged @ rack rates.