Today in Minzamar my sorcerer got _hammered_ by negative energies I should supposedly have 50% DI against with my Shield spell active. Resetting perk and recasting Shield did not work. Finally met her deserved fate at the hands of a swarm of shadows. O.O
The Shield spell with this perk also fails to deliver constant AC in combination with Greater SF: Abjuration. As soon as the caster undergoes any form of change in deflection AC, there is a loss of 4 or 5 AC and the spell must be recast to recover it.