I doubt any of the airline CDP's are any better than the Amex Centurion as most are 5% & at most 10% - there are some other CDPs that offer better discounts though - but the perks are limited.
What makes the Amex Centurion CDP that good? Anything better included - the old Amex Plat used to offer 4-hour grace return, but they don't even have that anymore.