Barb is one of thoes classes that actually work as intended. I'd say dont touch it.
Even tho i agree that sin, demo, brute conq and DT is a bit strong, every class has been stated as op in its own way on this forum. Every class partisepate in pvp alot and imo the balance in aoc is fairly good. Atleast compared to what it was (w/comboskipping, bs 3k critcharge etc.) We also have to keep in mind that its the pvp ignorant fc that develop the game. We should be more than happy with the current balance.