Coolant is complex stuff, and the wrong coolant can do serious engine damage over time.
Until [insert manufacturer name here] says I can put it in my [insert car name here] without no ill effects, like voiding my warranty as Steve
alluded to, or corroding internal components, or plugging my radiator, or any other issues, I'll stick with the recommended fluids.
Another claim they make: "No Water - No Overheating
Classic Cool 180° has a boiling point of 180°C and will not boilover."
This is disingenuous at best. There is a difference between overheating an engine and boiling over. 180C = 356F. If your engine has an issue or there's a leak in your system that causes your car to run too hot, OK, this stuff won't boil over at the lower temperatures traditional coolant will. It's misleading to imply that this coolant will somehow prevent an engine / cooling system with issues form overheating, though.