My initial thoughts:
Priest utility just got absolutely crapped on with nothing to compensate for it. Encounter design matters more than anything.
Holy
I posted here: Feedback: Priests - #15 by Caithyra-bleeding-hollow
On the tier set bonus: It looks really strong for M+ and encourages an Empowered Renew playstyle for raid. I can already hear the Priests who hate Renew about to scream their lungs out.
Disc
They simplified the dps rotation A LOT (thank you).
It works like this now.
Mind Blast is on a 24s cd and it triggers Power of the Dark Side (50% buffed next Penance cast). You also get a +10% dps buff for 9s after using Mind Blast. Mind Blast is the new button you press when you need quick burst atonement healing.
Shadow Covenant gives you a 25% dps buff for 23s when you use Mind Bender/Shadowfiend so the no brainer talent choice is going to be Void Summoner. Mind Bender is going to be our burst healing ability.
TE is kind of pointless now because Mind Blast has a 24s cooldown.
In-between that you literally just have Smite and Penance. There’s no weaving of spells. 90% of your rotation is just going to be mashing Smite and Penance. A much simpler spec to play now.
They also gave Disc an actual raid healing cd. Ultimate Penitence is just cracked.
For the tier set bonus I have no clue how the 2-piece works. Is that for all atonements? I don’t understand the power of the 4-piece either.
And lastly: there’s no instant cast radiance talent.
Overall Disc is looking to be far better than Holy come next patch.