Dexcool was the official recommended coolant in the car's original owner's manual and the Haynes Repair Guide. It's also currently sold at auto parts stores with a giant GM logo, with years and models listed directly on the bottle, boasting itself as the official recommended coolant for my make/model vehicle.
With that much official endorsement, you'd think I could confidently use it without googling around but now I've heard from multiple people that it can cause problems, at least in high mileage vehicles. Whoops! It's frustrating when strangers on internet forums are more helpful than the official literature provided by GM.
