I was one of the people who contributing to getting the exact formula for spirit shell. You can find it on the EJ forums, but I also posted it on the beta class forums. With 6.36% crit and 30.41% mastery ss-PoH heals for 24% more than normal PoH. For Gheal and other direct heals it is 33% more, but PoH is the one that matters for aoe healing. This does not change too much for a relatively wide range of mastery and crit values. If your values dont match this then the most likely source of error is failing to properly calculate the contribution of aegis, mastery and crit to normal heals. For example on beta PoH heals for ~18k according to the tooltip, but if you add aegis, crit and mastery its actually 27k. Spirit shell PoH is 34k
Here is an example of perfect synching on elegon:
I am hitting 58k, but that is only because we are practically 3 healing it. Even so this is at peak and with heavy mana expenditure. He was bugged this try so we could not get into p3, however from past experience I can tell you I would finish that run at roughly 45k. With 5 healers I am in the 35k mark. Here is the same as holy but this time with 5 healers and for essentially the whole fight.
The monk above me was below me when we entered p3. He just went all out and built the lead you see in under 2 minutes.
Here is a recent example from blade lord in the heart of fear. I took a screenie in the middle and the end:
This is a great fight for disc, since it is very bursty without much sustained aoe. Disc is pretty much at 40k. The shaman hit 50k in over 60% of the tries.
The values I posted are what I see ppl doing in LFR right now on beta. I know I am not under-performing because I am pretty close to the theoretical maximum throughput, given the nature of the encounters, and so far no other disc priest in LFR has come anywhere close to me (which we can expect since its LFR).
FYI I was in the top 20 disc in WoL for most several fights on normal and hc DS before they started nerfing it. On warmaster I am still rank 20 disc even though I havent done normal warmaster for a very long time: worldoflogs.com/rankings/players/Dragon_Soul/Warmaster_Blackhorn/25N/Discipline_Priest/?page=1#p-15552457. On the first week of DS release, I was in the first page for every fight and was briefly rank 2 disc on Madness. I may not be the best disc priest eu, but you can bet I know I thing or two about maximising throughput.