I see a lot of points, but with this thread I didn't like to compare AST to the other jobs. (I guess there's a lot of threads doing it already), but with themselves. Like:

What would make me choose Diurnal over Noct?
- 5% Spell Speed buff
- Regen effects
- More reliability, regens stack, more healing power(counting all ticks of Hots), synergy with TD, synergy with both other healers.
I couldn't go wrong with this.

What would make me choose Noct over Diurnal?
-5% healing buff
-Shields
-More instant healing, TD usable for cards only, shields overwrite, fighting SCH for shields
I see that you can't use it all the time and you can't use with every partner.

The big question is, What could make me choose Noct more often?

If I had better cards with Noct, maybe I wouldn't mind playing alongside SCH, shields may not stack, but the better buffs could make up for it without making Diurnal worse...

Do you think it could?

Today we have a majority of Diurnal ASTs on PVE, what could make you guys choose Noct more often?