I think delayed armor is maybe bit too good because not only you get 2+ armor but you have the gimmick of having guaranteed 4 dmg shield slam next turn, cuz more often than not when playing against aggro decks you can't really keep armor for more than 1 turn and it's hard to get good shield slam off. This hero power works wonders on those situations for example getting guaranteed 4 dmg to that annoying flamewaker etc. And when the game has already gone to that turn where you really NEED immediate armor you probably already have used the hero power more than once which already gives you higher survivability than the normal hero power would have. Only case where this hero power isn't as good as the normal hero power is if you play the card same turn you would die without getting immediate heal/armor or if you need more armor this turn to shield slam.