Yeah, I mean how does this material actually perform on a roof? Is there a measurable difference in the marginal gain of 95% to 99.6% when analyzing inside temp

Yeah, I mean how does this material actually perform on a roof? Is there a measurable difference in the marginal gain of 95% to 99.6% when analyzing inside temperature of a house or energy reduction as a result? There seems to be many factors when looking at the actual cause and effect especially when cost is introduced.