The common consensus is that schs raid mitigation, emergency healing, mp management, consistent dps and fairy healing, make him somewhat irreplaceable. On the other hand, as long as the content isn't bleeding edge dps, and no mechanic that can hit above current hp totals, ast/whm fit just as well. Buffs to asts shuffle/cards (now redraw), enmity, and mp management should have stopped the stigma by now. Whm still is the almighty Aoe healer and has the highest burst dps between pom, stone 3, aero III and assize. All three healers suffer from accuracy, whm the most, but with the addition of melding, the hit rate can approach or pass 100% on current content.