I am a "raider". I mained scholar for a year, and used WHM for raid as well for one month. I have experience in cutting-edge progression from T6-T13, my group was also Lamia's first-clear group on T11,12, 13. I hope these would support my opinion and feelings about this new healer job.
Overall this job feels underwhelming, it requires high skill to play well, but the rewards in return (those buffs from cards) is too small and even negligible most of the time. I feel there's something seriously wrong with the statistic tuning of the skills (buff potency/duration/radius etc.). If I had time I would write a detailed thread myself.. But please consider buff this job as soon as possible (Before Alexander raid comes out).
Below are links from both US and JP forums that shows how disappointing most of the AST players feel:

http://forum.square-enix.com/ffxiv/t...n-so-far/page9

http://forum.square-enix.com/ffxiv/t...4-占星術師スレ/page5