On the plus side I liked the idea that it is a one time deal, and runs under "0" pressure so hoses last for ever also. On the Negative side I worried about the fact that if ever there were a roadside or on the road type of service required,ie water pump,hose, etc. I would have to add water to the system and that is considered a contaminent to the NPG coolant which must then be removed iether over time running or by replacing the coolant. Ane the cost was or is indeed high. I always carried a gallon extra in my motorhome in the hopes that if needed that would get me to a safe spot. In our CTDs a gallon is like a drop in the bucket. Oh well things to ponder.