PA would ruin SG snipers and bursters.
And what's the problem?!
You get armor to counter damage, not to change your sprite. You should last more if it should have any use.
The far biggest problem with Powered Suit is the strength bonus. While it is somewhat balanced and does not really give anything very much extra, the people WILL do new characters just to move points from STR elsewhere, creating kind of PA alts. Bringing this kind of material would require some changes to how the game works, if it is supposed to make game more fun.
You can imagine how tricky must it be to introduce valuable item, when everything can be lost in a heartbeat, and players can freely create more characters to stockpile no matter how rare stuff, if it's going to be grind based. If one go for random based acquisition it'll be just as much unfair, only more annoying.
Personally I think it'd make more sense to see a limited use in controlled scenarios (PvP and PvE, just like players joining BoS or Enclave and fight each others for some objectives, or just going out with their faction for some dungeon or whatever) where nobody get's advantages. Even though alts will be everywhere, it can still be fun. But not everyone likes "theme park" style ideas.