If you want to be playing suboptimally then yes, use the power ones. For pretty much all DPS and healers you want to use the main attribute augments, which is why they sell the best. Diminishing returns for your main stat don't start really hitting hard currently until somewhere around 6000, so at that point the power augments would be better, but since it's impossible with current gear to get even halfway to that point stacking your main stat with augments is optimal for DPS and healers.
Power gives slightly more of a boost to damage than main stat does. This is balanced by main stat increasing your crit rating slightly. However, once you're at your crit goal, or if crit isn't useful to your spec (which it isn't for some bc of procs that auto-crit) you want power over main stat.