I can't seem to make it worth for any build. Power armors like Roz's armor and LUCK seems to harm more than help.
Power armor is slightly better on ranged builds in general, because you can use the rouser as your melee weapon, which gives 10 evasion.
Very counter intuitive, but smugglers can make great use of power armor. The Lv. 4 perk agility not only negates the negative evasion, but it gives you a bonus on top. With no other evasion gear a smuggler has +10 evasion in the ramshackle power armor (Roz Armor), instead of -10. With the following equipment you can get to 40 evasion and 45 evasion when the Lv. 10 perk Cloak and dagger triggers.
Melee: Rouser
Ranged: Royal shard bow or Zil champion bow
Chest: Ramshackle
Shield: Bio-enhancement Shield
Acc: Light Jetpack
Lucky breaks increases your armor the more evasion you have. With the mentioned setup you sit at a whopping 33 armor and +50 health. Of all the classes, the smuggler is the least dependent on weapon base dmg, since most of their dmg comes from aimed shot or sneak attack.
Another stupid strong synergy is the booster pack ability. It says that while flying, aimed shot and sneak attack trigger even if the target isn't blinded or stunned and doesn't fly itself. If you are flight capable, which means certain wings or the light jetpack, you still get this benefit without activating the ability during combat. Which means that the light jetpack triggers aimed shot and sneack attack without any setup.
However I would not recommend the behemoth scale from Dhaal. -15 evasion is hard to offset, even for smugglers and is inferior to the ramshackle setup. Also -10 accuracy sucks.