I don't really see how IB 20% dmg shield is being compared to rampart. Pallys block ~45% of the time and parry ~25% of the time. Having IB reduce dmg by 20% for 6 seconds is basically allowing the warrior to block for 6 seconds. How rampart and IB compared when a pally uses rampart he is still able to block 45% of the attacks further reducing his dmg taken by another 20%?