Is the top one AH2 and the bottom AH3? Or are they both AH3, one with shadows and one without?
I have a feeling the "washout" is cause by the intensity of AH3's sunlight. Its not just skins - have you noticed sunlit cumulus clouds? The detail disappears and the cloud bank becomes just a bright white mass.
I found with the P-38 and P-51 I was working on, I had to darken the metal several shades as a start. But that has drawbacks when viewing the non-sunlight side, or when the sun is behind clouds - the metal texture can then look too dark and blotchy.
I don't have a good understanding of graphics and 3D worlds and all the issues, tradeoffs, and even the correct terminology that should be used, but it seems to me like the light source for direct lighting (the sun) is far more powerful than it was in the past, and ambient lighting was either reduced or appears reduced in comparison.
A related (I think) problem I've noticed is that when I've achieved a good balance between the specularity (shininess/glare) and environmental (mirror reflections) effects in bright sunlight and my metal looks very believable to me as I pan across the skin and the sun angle changes - if I then go to the other side of the skin, the non-sunlight side, my specularity effects drop to zero and all that's left are the reflections, which makes the metal look more like glass.
I'm still early in the process and I haven't been able to experiment with the effect of Power map changes yet.