Wow.

I remember how sleep used to be awesome in dungeons when we were first tackling arr dungeons and not v geared. Pull a pack of 3, sleep, focus fire 1 down then move onto the nrxt. Its not actually slower than aoe-Ing them if you are barely geared for the content...

This whole aoe thing only became 'popular' because tanks and healers became overgeared and can pull like 6 to 9 mobs at once, thereby making aoe strictly more efficient, but only if the tanks and healers can handle it.