Pre-50 dungeons and at level runs, sleep does really well as does other CC methods. Once people are overgeared, it doesn't matter though and AoEs are much more useful. There are some groups of course where this is not so.
Tank/Heal/MNKs (I'm pretty sure mnk doesn't have much in the way of AoE...)
Tank/SCH/SMN/BLM (SCH+SMN Bane DoTs will not break sleep so BLM can sleep and burn targets 1 by 1 while SCH+SMN DoT to death).
Tank/WHM/SMN/SMN (Same as above, WHM sleeping)
Most other combination of DPS will probably find more use out of AoEs, but particularly in DF not everything is so clear cut. Remember to change and adapt to the setup as each run is different.