Anyone have experience with ES12a or equivalent hydrocarbon refrigerant? It's apparently not authorized in US for auto AC systems, but seems to be pretty common in other parts of the world. this site says it is now available, AutoRefrigerants and HomeRefrigerants, and seems pretty reasonable cost. anyone in denver area want to split a case? no need to pull a vacuum, direct replacement for r12, blows colder than r134. What's not to like?