What is the point of having POWERED armor if you aren't better protected, faster and stronger than someone not wearing it?
Personally I don't envision FO3 PA as being like high tech Japanese manga armor. I see it more like a post war ('50s) heavy tank. Very heavily armored but relatively slow and not agile. The powered element allows it to hold its own weight and manage heavy weapons, but not leap and run like a dancer.
The look and design just doesn't fit an agile 'Ironman-like' movement to my mind.
In my game, I have increased the defensive characteristics to the point where it is nearly invulnerable to light weapons (no more 10mm headshot kills!). I have also increased the rad resistance, boosted ability with big guns and given it water breathing capability. I think this fits the image, and gives an awesome heavy tank feel with schlangster's Helmet POV mod.
I don't want it to become an uber weapon though. Like a heavy tank I envision it to be intended for direct assault on heavily defended positions and point defense against overwhelming numbers.
But of course, you don't do recon or commando style raids with a heavy tank.
So similarly, I would like to make Power armor a bit too slow, cumbersome and noisy for general wasteland exploration and stealthy missions.
I imagine it as the type of thing you would don to assault the water purifier, but a bit too slow for everyday use without a measure of frustration.
Hope that clarifies what I am aiming for.