My understanding was more towards the way Devil explained, and the power map is fairly dark already, but I can make it even darker.
But, Skuzzy's use of the phrase "narrowing the specular effect" make me think he wants the bare metal reflections more focused, and thus a lighter, not darker map shade should be used for the bare metal.
One of these days I'm going to do a chart which will list all the typical elements of an AH3 skin and the suggested range of values for the Specular, Power, and Environmental maps.