After installing the ECS Tuning/NewSouth Performance Power Gasket and putting the car back together I went out for a drive to log the temperature of the intake manifold.

The car had not been driven for a few days while the swap was taking place, so the IM was starting off at ambient temperature, but due to the car being in the garage and the drive taking place at night as the temperatures were falling the IM temperature starts higher than the outside ambient temperature with the gasket in place.

The results are unambiguous to me that the Power Gasket does little, if anything, to lower the temperature of the intake manifold at the point along the runner that I am recording temperature.