All the aura does is a 15% damage boost to pets within the area (and only those within your group). The difference between this and Rathe's Strength is the new aura is centered on you while the old is centered on the pet. This gives you greater control of removing it at whim and it lasting more reliably across zonelines, but you sacrifice by having to be close to your pets at all times.
The suggestion above about suspending to keep the effect on the primary pet isn't necessary anymore with the lvl86 Burnout rk2 spell (which adds a 15% boost by itself). The only question now is whether you can stay close enough to your swarms for it to affect them. If yes, use Arcane Distillect. If no, use Rathe's Strength.