So, concerning Disc Priest tank healing, I'm trying to think out of the box here. I've come up with a spec, in which I hope you all can evaluate.

53/18/0 - Disc Tank Healing

So, in this spec, I forgo a few talents to get Improved Healing in which I will make my case in why I did so.

The Disc Talents Changes

1) 2/3 Enlightenment - With the absurd amounts of haste on the current gear, there is no possible way to stop at the "hard cap" (which I know we've been talking about being the wrong term for it). Be that as it may, since Spirit is only so-so for Disc the 2% drop in that and haste doesn't make me want to max it out. The only reason I put two point in it in the first place is to get to the next tier.

2) 1/3 Focused Will - Basically the easiest talent that I could drop to preserve the best raw healing with most healing spells. A Disc Priest's crit is already going to be high, but 2% is 2%. You could alter this spec somehow to get these 2 points if you really want to.

3) 1/2 Grace - This talent is tricky. If you're raid shielding, theres really not much of a point to taking this since it doesn't proc off of shields and if you cast Flash Heal on a raid member, chances are you won't have to heal them against with Flash Heal because they are now topped off. On the other hand, if you are assigned to tank healing (and assuming you don't switch healing tanks that quickly), you should be able to maintain 3 stacks easily on a tank. The effect lasts 15 seconds, and you will be healing your tank target within that 15 seconds multiple times, so it will get refreshed. There's not really a point to doing 2/2 Grace unless you are healing multiple tanks.

The Holy Talents

1) 2/2 Healing Focus - Used to get to the 4th Tier. Filler points mostly, but if you are tank healing, its best not to get interrupted. I always prefer the cautious route.

2) 5/5 Divine Fury - You're tank healing, and you'll most likely be casting Greater Heal quite a bit (according to my theorycrafted spec and playstyle). Personally, in all situations, I prefer Divine Fury over Spell Warding because one, if I need to add my DPS to the boss, I can do it quickly, and two, if every other raid member can survive without 10% spell damage reduction, then so can I.

3) 0/1 Desperate Prayer - Being Disc, I recently discovered that I almost never use Desperate Prayer. Why use that on myself when I can just shield myself, giving me Borrowed Time, a chance to proc Rapture, and giving me a shield that absorbs roughly the same amount as DP? Of course, you could always throw one point from Healing Focus into this if you really wanted it.

4) 3/3 Improved Healing - 15% mana cost reduction on Greater Heal and Penance (and Divine Hymn if you dont Inner Focus it) is godly for tank healing. Brings the cost of Greater Heal down to 1050 mana and Penance to 525 mana.

Summing It Up

The purpose of this build sacrifices 2% crit, haste, and spirit, as well as 50% chance to proc Grace (which should be easy to maintain on a single target anyways) for 15% mana reduction on Penance and Greater Heal. Currently, with exactly 500 haste rating, my Greater Heals are a 2.086 (1.669 with BT or Power Infusion) second casts and my Flash Heal is at 1.251 (1.001 with BT or Power Infusion) second casts. This is without raid buffs.

Here's some self-buffed data (assumes 3/3 Grace, ~3000 Spellpower):

Flash Heal (non-crit) ~5000 healing
Flash Heal (crit) ~7500 healing
Greater Heal (non-crit) ~10200 healing
Greater Heal (crit) ~15300 healing

Cost of Flash Heal (glpyhed, talented): 521 mana (417 with Power Infusion)
Cost of Greater Heal (Improved Healing): 1050 mana (840 with Power Infusion)

The mana costs are roughly the same. Flash Heal will have a better crit rate when the target is low, but Greater Heal will continue to benefit from haste when Flash Heal reaches a cast time of 1 second. And I haven't even talked about the 15% mana reduction on Penance.

Thoughts anyone?

Trading 2% crit, 2% haste, and taking longer to stack grace on tank switches for unneeded mana efficiency doesn't sound very appealing. With current gear levels, we are trying to go the other way with dropping efficiency for more throughput. If you're having trouble running out of mana as Discipline, try using your mana return cooldowns properly, drop Greater Heal as your filler spell in place of Flash Heal, or raid with better dps.

If I were going to be 100% tank healing, I'd swap out most of those +23 sp gems you have, and replace them with 12sp+10int. And I'd stick with my current spec, the typical disc spec, but take Divine Fury over Spell Warding. I think the 2% increased crit and haste is going to be much more vital than the 15% mana reduction on greater heal and penance. It's a 4% reduction of stats to gain 15% reduction in mana, that I feel can be made up with mana via int gems, without losing anything but some spellpower. Mana seems very trivial in ICC thus far though.

Your crit heals you listed seem a little low compared to what I see, but I have a bit more crit than you, so that's probably where I'm getting the difference. I am a crit and int whore though.

Hello, I see people advising to gem int for tank healing (disc) and I can't understand why?

I usualy spend my mana faster when I spam shield the raid than when I spam heal a tank. Plus, I really feel like my FH is never big enough: A 5k heal on a 50k hp tank feels ridiculous.
So I go full sp on disc, wether I spot heal or tank heal.

The only reason I see to gem int, would be for GH spam. But I use this spell very carefully in the current content.

On a sidenote, there's decent int trinkets from badges for easy swapping.

I never said I was running out of mana. I didn't propose the build because of mana issues either. I proposed it because more gear is either crit/haste, crit/MP5, or crit/spirit. There are a few exceptions, but thats not the point. My point is, I don't have mana problems, so I don't need to stack any more MP5 or spirit, which just leaves haste, but I'm already sitting at around 500 haste, and my projected-future gear will have more than that.

Which brings me to my point. We're getting so much haste from gear these days that the 2% haste lost from Enlightenment isn't a big deal. The 2% crit might be, but personally, my crit is already set to rise by 4% or so in the near future. The point of the build was to shed a few points from no longer needed talents and throw them into Improved Healing to improve Disc Tank healing. The Grace issue barely deserves any mention, as it's only good for Disc Tank healing, and if you're tank healing, chances are Grace will have nearly the same uptime on 3 stacks, it will just take a little longer building them up initially.

With my proposed build, you get more throughput because Greater Heal heals more than Flash Heal (sans T10 2set). And you most likely won't have to gem into SP/int, or at least not as much, giving you more room for throughput gemming.

Once again, I am not having mana problems, and I didn't propose this build because of any sort of mana issues. I proposed it because with the insanely high haste and crit ratings, do we really need that 2% to haste and crit? Why not expand our roles a tad bit and improve on tank healing a little.

I highly doubt you're haste capped with Greater Heal if you are disc tank healing. Remember, haste is always valuable if you're going to heavily use Greater Heal or Prayer of Healing. (And by choosing to get Improved Healing, you've indicated you plan to use Greater Heal).

Yup, I swap as you can see as well on armory, and always gem to get the bonus.
The only not sp-oriented gem I have is the belt socket. When I go sp gemming, I pick sp as much as possible keeping the boni. I also switch 1-handed + offhand / staff depending on regen needs.

And of course penance, PW:S etc... What I mean is: penance on CD, weakened soul up, tank is low, your FH doesn't crit = sucks.

But I still don't know why int is better for tank healing.

To Cascade-Mok:
You're trading regen against haste/crit via your talents. If it works for you, fine.
Check how many GH you cast per fights, see how much mana it gives you, and compare with the stats you lost. Maybe getting the extra regen from your gear would allow you to get better overall? People don't like GH because of the overhealing and more spiky healing on the tank mostly.

Interesting. Have you considered dropping Improved Flash Heal and the Flash Heal glyph instead? Your point about landing a shield but not having a time for a Flash Heal on a raid member is well taken, and consistent with my experience. I've been looking for something new to try with my alt Priest after raiding as Holy for a couple months; I think I'll try your build.

edit: something like this Talent Calculator - World of Warcraft

Here's some math comparing a Divine Fury'd, Improved Healing'd Greater Heal with a glyphed flash heal in a Discipline spec.

Greater Heal
Assuming 3000 spell power, ((3950+4590)/2[BaseHeal]+3000[SpellPower]*161.11%[Coefficent])*1.1[FocusedPower]=10366 heal
With 25% crit and Divine Aegis,
10366[HealAmount]*75%[Heal%]+10366*1.95[CritAmount]*25%[Crit%]=12827 average heal amount
With a 2 second cast assuming 11% haste from gear, raid buffs, 5/5 Divine Fury, and 2/3 Enlightenment
12827[AvgHealing]/1.96[CastTime]=6544 Healing per Second
12827[AvgHealing]/1050[ManaCost]=12.216 Healing per Mana, and 1050[ManaCost]/2.00[CastTime]=525 Mana per Second


Flash Heal
Assuming 3000 spell power,((1887+2197)/2[BaseHeal]+3000[SpellPower]*80.68%[Coefficent])*1.1[FocusedPower]=5074 heal
With 27% crit (2% more from Focused Will) and Divine Aegis,
5074[HealAmount]*73%[Heal%]+5074*1.95[CritAmount]*27%[Crit%]=6376 average heal amount
With a 1.16 second cast assuming 11% haste from gear, raid buffs, and 3/3 Enlightenment
6376[AvgHealing]/1.16[CastTime]=5496 Healing per Second
6376[AvgHealing]/521[ManaCost]=12.24 Healing per Mana and 521[ManaCost]/1.16[CastTime]=449 Mana per Second

You will have higher burst healing from using Greater Heal over Flash Heal, not figuring any overheal amounts, but with an increased mana cost. The increased burst comes from Divine Fury, but taking Improved Healing doesn't make Greater Heal more efficient than Flash Heal. I would recommend getting the best of both if you don't have mana issues, and drop Improved Healing for throughput but keep Divine Fury. You have your increased burst on demand, but flash heal will still be your filler.

Edit - Why trade throughput for mana efficiency, when the goal of this spec is more burst healing? Then, this argument is basically Divine Fury vs. Spell Warding and Greater Heal vs. Flash Heal, two of the most often debated topics here along with gemming Intellect vs. Spell Power. Also, 53/18/0 is discussed in the first post.

For a tanking build, I don't think I would personally drop Imp FH. I would drop Focused Will first. If I knew my tank wasn't going to take heavy hits, I would still probably FHeal them to ensure that I would never get behind in healing. The 25% reduced mana cost would be too great of a loss.

I didn't include Grace's effect (neither did I include Tree of Life bonus effect, since they are target debuffs), and you didn't include Wrath of Air haste in your casting time. That's why your computed HPS and MPS are a little lower. The mana reduction percentage for the flash heal glyph and talents are removed from the % of base mana, my flash heal mana cost is correct.

To calculate Casting time with a given haste is CastTime/1+([Haste%FromGear]*[Hastebuff1]*[HasteBuff2]*[HasteBuffn]/100)