Been around for awhile. I've heard good things about it. Some guys on the CR5 forum I belong to run it. I believe you are supposed to run it with zero pressure in the system. I've heard it does work and help you run cooler. But, if there is a problem, there is a problem and when you overheat and lose some fluid you can't just add water like you would with normal coolant. Shouldn't be a problem since we have an expansion tank though. Other than that, only downside I've heard is cost.