In principle you can get about 2x Consecrations off for every Execution Sentence, so 810% AP on 2+ mobs means it's superior DPS (before Judgement debuff at least, but then just add a 3rd mob for Consecration etc). It also doesn't consume HP. On the other hand, you require 9 seconds to deal all that damage, which isn't great when standard operating procedure is to blow everything up ASAP.