The warranty approved product is only available from the DC dealers. Amsoil and other's who claim to have a 'warranty approved' product are lying - they may have a product that works, but it is not approved by the factory and could void your warranty. This will be a personal choice if you choose to use this and then have a problem, your 2500 transmission may not be covered by the factory.
DC has the additive supplier and the two lube manufacturer's who blend it agree to only supply DC. The ILMA (Independent Lubricant Manufacturer's Association) filede a law suit last year and lost - the US Governemtn did not think this restraint of trade (re- free trade in the US) was effecting enough people so they chose to rule in DC's favor.
If you still have some of yoru 100,000 mile warranty left or have purchased an extended maintenance agreement, you might want to use the factory fluid to keep you warranty enforce without creating any reason for it to be voided.
Cheers,