Roy, Here's the blurb from Power Service's website about the "Slickdiesel" in their product. I don't know how it compares to other products, but I know I feel better about using the ULSD when I add it.
"Contains Slickdiesel for Maximum Fuel Lubrication
Slickdiesel sets the standard for lubrication of diesel fuel injection systems. The components of diesel fuel injection systems are lubricated by diesel fuel. Without proper lubrication, fuel injectors and pumps are subjected to increased wear rates and premature failure. Diesel Fuel Supplement +Cetane Boost contains Slickdiesel, a proprietary Power Service diesel fuel lubricator that exceeds the ASTM D-975 maximum specification for lubricity in Low and Ultra Low Sulfur Diesel (ULSD) fuels."