I have a priest only lvl ~45 and AA/A spec obvs for leveling purposes, but I was wondering how much worse it is at max level than the "regular" disc spec. Should i favour more haste for my AA/A spec so I dont have to reforge when I switch to holy since I want to have a holy and disc spec or go all out on mastery which weaken my AA/A spec alot since i am healing more than sheilding.
As a haste-favoring Holy Priest with an Atonement off-spec I can say that it works just fine at max level. You can't just rely on Atonement, but the entire spec supports much more than just Atonement.