I find Fluid Aura much more useful as an "execute" of sorts on regular mobs. If the target is almost dead, you can throw out Fluid Aura + Aero, and if you screw up and the mob didn't die then the mob will just wonder back since Aero will remove the bind effect. It's something you have to practice though, and really try to get into the habit of only using it on mobs that are nearly dead or using it in your rotation against mobs that cannot get knocked back.