Well I would agree that mixing of the coolant was an issue but I would also say the decision I made was after hours of reading on many different sites and many accounts of life experience and chemistry. GM is a profit center and we must not buy into the line that everything they say, make, or approve of is in the consumers best interest.
Right because people on the internet are the experts. Are you a chemical engineer? I'm sure GM spent millions to design a coolant that purposely destroys their own products because they're a "profit center" (what business isn't a "profit center" anyway?). Do you realize how crazy that even sounds? Show me one instance where Dexcool was proven to have caused an issue in an engine that was not a 60* or 90* V6 with failed intake gaskets. I'll wait. The poorly designed/implemented intake gasket does not apply by the way because they realized they made a mistake and FIXED it with a new metal gasket (darn, but what about the profit center????).