I agree with you: one data point does not a trend make. That's why I asked for more feedback from members. There has been one published SAE paper questioning solder protection with OAT coolants, and that has been contradicted by Texaco and GM. There is ONE weakness with Dexcool, well-documented by GM, resulting from poor coolant maintenance: if you let your coolant level drop, the coolant can form precipitates on radiator caps and in coolant bottles (shown on GM cars). The solution is simple: just make sure the level is at the minimum mark.

Ford and Daimler-Chrysler have been a little more conservative about coolant technologies, and recently approved the OAT-plus-low-silicates model used by Glysantin (Zerex/BASF) which will be sold this year in the US under the Zerex brand name. It has a little more aluminum protection and has been used by Mercedes for some time.