Lads I also have the power gasket installed and the results must be more benefit than not. Before it went in if you put your hand on the intake manifold after a decent drive in Brisbane you would probably leave half a hands worth of skin on there, but with the power gasket it's quite cool to touch. They say that every 10 degrees of heat you loose approx 1% of power so it must be helping at least a little.
And also I think there may be some confusion. The link provided is for the power gasket. Relatively thin and no gaskets as Troy mentioned. Then there is the phenolic spacer as noone posted in the first post. There is a huge difference imo. The phenolic is about 2-3 times thicker and is ridgid, so both keeping the heat from the head further away and absorbing the transfer heat better. It seems to made from a different compound resin that sets hard. It also comes with gaskets and longer manifold bolts to be used because of the thickness. I rekon it's the way to go for sure and here is the link
Intake Manifold Spacer, 1.8t, Phenolic - 034 MOTORSPORT