I have payed IB on live a lot and my most favourite build was 2H cawe-iin with AOE snare,heal debuff,absorb bubble:
http://waronlinebuilder.org/#career=ib; ... 0:;0:0:0:0:
Even on live playing IB was the most tough melee gameplay because ofusing so many skills my action bar slots were all filled.
I never played BG so I have decide roll one on RoR. What a surprise, that playing BG on 20 is even harder than IB. He has significaly lower dmg outpoot than IB thanks to absence of heavy blow,dmg increase scalling with hate for offensive attacs, but has toughness and wp/int debuff.
At the end IB has more buffs( armor, corporal resists+self 50%AA speed), while BG has more debuffs(wp/int, toughness) and absorb bubble.
IB has has knockback While BG 5s knockdown.
At this level BG can buff his toughness up to 45% at 100 hate thanks to specable tactic Terryfying foe but its horribly conected to PvE skill Hatefull strike which generate double threat (agro) and will be never used in PvP without it.
My opinion is, that BG is tougher for him self, but in final is less effective for group than IB even at this stage. Player must use even more hotkeys and has less buffs for dark protector target(no armor or resist buff)
In further patches I would really like to see proper mirror to IB 2h spec(path of vengeance) because BGs 2h tree is competely nonsence for solo nor for party play.