Hello,
I'm a mythic raider with 35 points in holy/disc and I have more than 12 million banked up in AP. The reason is because I am not sure what will be better in Nighthold. I would keep stockpiling but I am currently running out of bank space and need to start investing my AP into one of the weapons. I play both specs similarly well (orange parses with both specs on multiple boss fights, etc). We don't have a boomkin to feed me innervates when I'm disc, but I know firsthand that you don't need innervates to make disc work ( some will say that having a boomkin will change the decision so I am just including this information.)
I know many people will say that it doesn't matter because I am not bleeding edge progression (I don't disagree, it probably won't matter) but it will make me feel a little better getting multiple opinions on which spec will be better come Nighthold. I have fun on both specs but I think that splitting my AP on both weapons doesn't make much sense. Therefore, I want to make a decision to spend some of this AP. I haven't spent much time on PTR so if people that have tested Nighthold fights and/or the priest changes could inform me of a better decision, that would be great.
Thanks!