From a raiding standpoint there are two aspects of AST I find less than ideal. The first is the standard RNG nature of the card mechanic, because while sometimes you get the combos you want anytime you get a chain of spire cards you just fill with dissastifaction. The other aspect is mana regen, of which ASTs have sadly very little. This is kind of a death knell for the class if your group is letting whirblewinds go off in a4s.

However when the stars align (/rimshot) and your card buffs go well they can really effect overall performance. Our WHM swapped to AST for a3s and the balance/arrow buffs significantly contributed to our overall success. The class is very viable, just... less so in a4s if you choose the mana-less route, especially when WHMs can bust out their new Assize as a secondary mana aid.

I don't want to comment on Noct as I am primarily a SCH and don't want to give up my indomitable king-seat of deployed shielding and fairy-heal assisted DPS. O-(-'.'Q)