The pieces are better defense wise for a tank yes, but the problem is the main weapon and the pieces for dps and heals are very modest increases. It's a case of both people being right; tanks should gear, but DPS and heals will only see modest gains since the bulk of the upgrades are in defense. To get better stats overall from augmented needs HQ whites at 64, or dungeon gear from 65 on. It might be an argument for them to scale stats a little more during levels, so that even NQ level-approriate gear is a decent boost over certain pieces.