I have played a fair number of games on my AST since the expansion comes out, and what I can say compared to the other healers is that it feels far too weak and needs something to help bring it up.
It's issues are that it has very little in the ways to help sustain themselves, and their teammates.
Consider that:
White Mages get Regens, Assize, Divine Benison Shield, Protect, and Fluid Aura (knockback AND bind) to help defend themselves and their teammates. Furthermore, Protect lasts longer than Disable, the cooldown is shorter and the cooldowns of all their other skills can be shortened even further by Lilies. This gives them many, many options to keep their teammates and themselves alive.
Scholars get powerful shield, Eye for an Eye, a knockback, powerful healing burst in Summon, and chain strategem and Broil's mana drain really helps their team gets kills fast. Summon is seriously really powerful.
Astrologians I find have little ways to defend themselves and sustain their teammates.
The only actual healing cooldown we get is Essential Dignity. Besides that, Lightspeed's main use is for kiting, it doesn't boost our healing output, so it doesn't help in defending our teammates. The synastry target gets an extra 25% heal when you heal them, so putting Synastry on the person being focused and healing them helps yield slightly higher heals. But we cannot use Synastry on ourselves. If we get lucky we can get Bole, but that's RNG and not reliable at all.
To top this all off, we have no mana regen except for a 1/4 chance for Ewer. Sure Lightspeed reduces mana cost but that can only take us so far if we get unlucky and never get an Ewer.
Then we have Deorbit.
This skill is very cute for pulling in people who try to run to the enemy base before boxes are even collected or for people who overextend into entire enemy alliances in Frontlines, but that's it. Literally, the only usefulness in it is when your teammates are bad. I toyed with the idea of using it to help ease damage on the target just for a bit by pulling them away from the enemy melee, but you have to be at a far distance for that to be helpful and you want to be at a moderately close distance for navigation around walls. And, this is the most important point, it does nothing to help Astrologians defend themselves! What this essentially means is that where Scholars and White Mages get an extra powerful defensive cooldown to help themselves survive such as Divine Benison/Protect/Fluid Aura and Eye for an Eye/Summon/Aura Blast, Astrologians get an empty slot. Combined with the lack of any Hots or Shields and Astrologians become a noticeably weaker healer who will fold immediately under pressure. Note also that all those WHM/SCH skills listed can be used on both themselves AND their party members. As mentioned earlier, AST's skills Synastry and Lightspeed are only useful for their party members OR themselves. All we got is Disable and Essential Dignity. Bole is there but it is extremely left to RNG when we don't have Redraw.
Our gimmick with Benefic making the next spell instacast, while cute, doesn't particularly help us since we still have to wait for the global cooldown. It's helped in the few situations that I coincidentally had the buff going whe nI got stunned so I could instacast out of the stun, but that's really situational and hard to get. What little kiting we can get from having one instacasted spell is sad. Whereas for WHM and SCH, their Lilies and Shields are always useful.
I think that Astrologians should be looked at and be considered for rebalancing before the season comes out. At the very least, give us a more useful skill than Deorbit. It feels like a waste of slot. AST needs something to be able to defend ourselves because Essential Dignity isn't enough.
If other Astros or healers would like to give me their opinion on the state of AST, whether they agree or disagree with me, I'd love to hear it. Some discussion would be nice. Maybe I'm just missing something about AST's new toolkit.