From our Coolants & Chemicals product manager:
The analysis I have on Cool Gard II is a few years old, but it does have an inorganic buffer, borate, (ES OAT does not) and it also contains silicate (ES OAT does not). They both are nitrite free and contain significant organic additive content. Both formulations are relying on organic additives for liner protection. Even though Cool Gard II has some inorganic content, I still consider ES OAT to be the best cross for the product, as the Cool Gard II product is nitrite free and is relying on OAT additives as the primary corrosion inhibitors. I can provide a more detailed comparison if the customer is interested, but we would probably need to provide a disclaimer that our test data on the Cool Gard II product is a few years old and it is possible there have been some changes in that time."