Since 6.0 is making all this null and void anyway, I wanted to share this so you can see how good one can do, if one thinks out of the box. NOTE: Two MAJOR out-of-the-norm changes to your priest are required! Two key pieces of gear are required, and you will (probably) need to reforge.
The two out-of-the-norm pieces of gear: Meta-gem needs to be the DPS Sinister legendary gem. Yes, Disc spec gets the haste proc, which is HUGE I cannot emphasize this enough! The other item is Kardris’s Toxic Totem. Yes a dps trinket! You DO get atonement off the multi-strike procs! You have to have good enough gear and spirit to back up this gear set, but SO WORTH IT believe me! Otherwise gear is normal healing gear including the legendary healing cloak and I use Prismatic trinket off Sha of Pride
There are two stats to prioritize when re-gemming/re-forging: Spirit and Crit. For reference, my priest is ilevel 565 and unbuffed he has ~14k spirit and ~13k crit-rating. Takes forever to go oom, and crit means bigger atonement heals/shields. After that, priority isn’t super important but I went with mastery third, and haste has lowest priority, since the meta gem procs so often
Talent-wise I use Mindbender, Twist of Fate, and Divine Star. For major glyphs I use Penance, Holy Fire, and Smite. For minor use Glyph of the Sha to take Mindbender off the GCD. Here’s the macro:
/targetenemy [noharm][dead]
/castsequence reset=combat Shadow Word: Pain,Inner Fire,Power Word: Fortitude,Alchemist's Flask,Crystal of Insanity,null
/castsequence [nochanneling]reset=0.3 0,0,0,0,0,Penance
/castsequence [nochanneling]reset=0.3 0,0,0,0,Holy Fire
/castsequence [nochanneling]reset=0.3 0,0,0,Smite
/castsequence [nochanneling]reset=0.3 0,0,Divine Star
/castsequence [nochanneling]reset=0.3 0,Shadowfiend
/use [nochanneling]Archangel
/run UIErrorsFrame:Clear()
Gonna explain the Shadow Word: Pain,Inner Fire,Power Word: Fortitude,Alchemist’s Flask,Crystal of Insanity,null line. Shadow Word: Pain is there for tagging purposes like Timeless Isle or what-not. As for the rest of the line, I enjoy not having to remember to self-buff. Feel free to remove this entire line if you want to
Power Word: Shield and other spells are intentionally absent. In LFR/Flex I never need to manually cast anything. This rotation rocks as is. For Normal yes some manually casting of things is ofc needed here and there. Never tried heroic on my priest, and I imagine nobody’s lazy macro really works with heroic all by itself, since lots of attention and manual casting is needed there
Otherwise this is a pretty simple macro which easily mimics similar ones in other posts. It’s the gear and stat modifications that really make it shine!
Enjoy