First, you have to fight the meter battle with various metermaids who link recount after every fight, and raid leaders who frown upon your low numbers.
Second, you have the raid leaders who lawl at the idea of having a Disc Priest in the raid at all, because, srsly, we already have Holies for our buffs - anything you can do, they can do better, right?
But a few patches ago, Blizzard introduced a new Holy talent that makes the whole bubbling battle even more frustrating.
It's actually been around for awhile now, and for the record, I have tried it out a few times. Yes, it is teh awesome. It was brought back to my attention while I was trying desperately to write a Holy Priest PvE Healing guide to go along with my Disc healing guide, which seems to have grown pretty popular over the interwebs. (Just so you know, it is in the works - it's just a lot more complicated to write up than the Disc guide).
If you were to check out my Holy Spec right now on Jessabelle, you would see that I am not specced into this wondrous talent, and for very good reasons, mind you. Yes it is useful - even in raiding. But I chose other options because I don't want to piss off my precious Disc Priest in my raid. I really do try not to piss off Disc Priests - I sympathize with their struggles. Plus, I do not want to get on Amber's bad side. She's way snarkier than me. /cower
So when should you spec into Body and Soul, and when should you skip it if you focus primarily on raiding?
Are there no other priests in your raid? SPEC IT
Are the other priests in your raid all holy or shadow? SPEC IT
Is there a Disc Priest in your raid who is dedicated for main tank heals? SPEC IT
Is there more than one Disc Priest in your raid? SKIP IT
Is there only one Disc Priest in your raid, but they are NOT dedicated to main tank heals? SKIP IT
My situation falls into the last category. But Miss Medicina! you may cry, Why on earth would you NOT have your Disc Priest assigned to Main Tank heals? ZOMG L2PLAY.
Disc Priesting is actually kinda new and novel in the raiding world since Wrath. Back in the BC days, Disc was pretty much our PvP spec. I never even gave it much of a second glace except to pick up Divine Spirit before it became a baseline spell. Then all of a sudden Disc Healing became viable in a raid, and not only that... it became pretty freaking awesome - and way fun to play.
Even now, there is this misconception that if you have a Disc Priest in a 25 man raid, they should always be on Main Tank heals, due to their strength in single target healing. Tosh, say I. TOSH. Single target healing =/= Main Tank healing. We have a Disc Priest in our raid who is moderately new to the style, and he and I have been whispering back and forth in obvious geekjoy, playing around with different things he can do, because we usually have far too many pallies. So, I usually assign him to wonky boss fight mechanics - Why yes, my friend, you are on Slagpot duty, and throw a Prayer of Healing or Prayer of Mending when needed, kthx.
And off he goes, into a happy bubbly oblivion.
What bursts that bubbly besottedness is some Holy Priest's damn Weakened Soul debuff on the Disc Priest's target. I'm one of those healing leaders that announces to the whole raid when we have both Disc and Holy priests - because I've listened to too many Disc priests complaining about Holy priest's bubbling their targets and screwing up the Disc rotation, not to mention wasting their abilities. And when Holy Priests have Body and Soul... they want to USE it. Because it's awesome. And it's handy. And if I didn't have my Disc Priest bubbling bombed, fisted, and slagpotted folks, that Body and Soul would come in handy - get a quick runaway you gravity bombed druid!
But unfortunately for you, B&S Specced priest, I do have someone taking care of that already. And even with your flashy Body and Soul buffed bubble that you want to use every chance you get, Disc Priest's bubbles are still superior. Sorry. Get over it, and go Circle of Healing something, mmk?