I am sorry, but this is just a wrong statement in so many ways.

I just showed that Flash Heal with 3/5 EH, 0/3 BR will be 5232 and Flash Heal with 0/5 EH, 3/3 BR will be 5047. That means that chosing to put points in EH over BR will make your Flash Heal 5232/5047 = 3.6%.

Are you seriously telling me that ANYONE can be "certain" that they save lives from a 3.6% stronger flash heal??! How? Just by intuitive sense? How can it be possible to feel that a 3.6% stronger flash heal helps save more lives? How can you not analyze everything analytically and mathematically to determine the highest healing output for your chosen playstyle.

This is not about whether you like to use renew or not, whether you like to use Gheal or not, whether you like to have SoL procs or not.......... the point is no matter what your chosen playstyle is there must be some spec that maximizes your healing output with that chosen playstyle. One spec MUST be better than another. Period. Whatever way you decide to play your priest, there MUST be some spec that is the best for it. And I am providing math to back up that analysis.

Even if your role is to do a LOT of Flash Heals, my claim is that Fheal is not going to make up 45% of your total healing and hence you will be better off putting points in BR instead. You will still save as many lives with a ~3% weaker flash heal and your overall healing output will be higher. Can anyone dispute this?

Basically, when you overheal the gain from the talents is lost anyway. So in reality on those heals which do not overheal benefit from the extra healing of the talents.

And, as others have said, it is not a healers job to output the most HPS, it is a healers job to keep people alive. For example, EH is simply superior to heal sag pot victims on Ignis. Sure, other healers might be better suited to do so, but perhaps the paladin healer is a 55 year old guy who is nice and all, but his reflexes are not that great any more. If you use FH to cover this, then EH might be better even if you do more group healing than single target healing.

On a more general note, this debate gave me the idea to write a simulation for this. Given a damage pattern and healing pattern, what is the survival rate of individual people. That way it would be possible to measure how often different builds/spell choices decide between life and death. It would not be so terribly difficult, but I fear that I will be to lazy so actually do so. Still I like the idea because it would quantify the "feel" we healers often express.

I do not agree with this statement: Even given that your healing mates have slow reflexes or whatever, and you are called to shoot around a couple of unnecessary FH in order to "cover" his target, the difference between life and death of a single person is really hardly made by a 3% stronger FHeal; Or, at least, in my ulduar experience just few times i saw people getting overkilled for less than 1k dmg after someone landed a direct heal on them; If they take damage twice is often due to their own error and really hardly a single heal of a single healer can save them; For instance, a situation where EH should win is mimiron p1 on napalm shells; but in this given situation most likely you will be supported by 3 other healers, and a slight improvement of your FH won't surelly make the difference in 99% of the cases, while that 3% more output will be really temptating during p2 and p4, even more if you are doin hardmode and you might run without a healer to match up the dps.
Of course there will be a situation where healing for 500 more would have saved a life, but it is irrational to downgrade your performance just for a not-so-much-likely-to-happen case;
Also because i see as a priest FH isn't the best situation often to save a life: generally i prefer to throw a shield on a single person who took a heavy spike (if there are no disc priests in raid ofc, but that's usually me so..) to allow him to run out of the aoe if damage is due to that and give other healers a bit more time to save him, but that's personal feelings.

This in actually the right approach. And depending on your damage and healing pattern, it may be mathematical tractable, in which case you even don't need any simulator.
However, you'll quickly find a limit of this approach : you need a damage (and healing) pattern, and results will be highly correlated to these patterns. How can you choose them accurately ? More importantly, damage pattern is bound to be valid only for one (or a very few) bosses. That's especially true for tank healing (where the frequency and size of hits on the tank is crucial), but that's also true for raid healing.

First of all, you can have "more than reasonnable" reason of this claim. Because you have enough AOE healing power, and never loose anyone during aoe (when you raid with four healing priest and 3 shamans, for example ;-) ). Or more likely, nearly never, compared to RST situations.

Or because you know that you use flash (or bind) heal when your target is low, and POH / COH only as a "top up" spells. Basically, you need to realize that not every point of healing has the same value. One point of healing is more important when it prevents immediate death, or heal a very low person, than when it put's your DK from 27k999 HP to 28k HP...

Ultimately, I perfectly agree with your conclusion. For anyone, there must be a spec that maximizes healing output. And they will be a spec that minimizes the death probability. The key point is that they are not necessarely the same, and computing mathematically one won't therefore give you the other (except of obvious points, like take meditation, SOR, COH...). Unless you prefer to play kikimeters, but that's another game.

Another way to look at this difference, which dps nearly never have : we play with finite horizon, when dps plays almost with nearly infinite horizon.
Basically, our horizon is the life of a person. With 20/ 30k HP, and the present damages in raid, players can die really quickly. On the contrario, dps tries to kill a boss, which last a few minutes, often more than 4. We all know that some specs are better on trash than others, but equivalent on bosses. The difference is really the fight lenght. When you need 15s to start your real dps, you're in bad position for trashes. For bosses, it doesn't really matters, that will be 4% of the fight length (for a 6 min fight). As long as healing is considered, we don't even speak of 15s time length, but more likely 5s.
If we had players with 300k hp, ie. if we have a long time for healing, then maximizing hps is equivalent to minimize death probability. That's the case when healing Razziavious adds, for example. But not for most bosses. The frontier conditions are not negligeable.

No. Your calculations may be "correct", but they are not really solving the problem.

You are assuming that "maximizing your healing output" is the goal, when it is not. Instead, we are interested in minimizing deaths. Until you provide some quantitative model for just how much each of these talents leads to a reduction in deaths, you really have not provided any real mathematical analysis of the problem. Sorry.

Yeah, exactly. Simulators can be very useful, but they are still models and have limitations. All simulations make assumptions, and when those assumption do not apply, neither do the conclusions. Some people seem to assume that numbers produced by simulators are inherently more accurate than others, and that is not necessarily so.

This is why I have implemented a more advanced calculator into the Rawr HolyPriest module (Custom Rotation). This lets you ask Rawr what it thinks given an EXISTING fight you had to deal with, with your raid variables. I have used this quite extensively myself, and it has really made me change some things around.

Please read carefully. I do not claim it to be so. I simply state that your conclusion is not valid. I am not sure I would make the claim that slightly larger FHs save more lives. But perhaps they do for them. Each raid is different. Perhaps they do for me, and I just don't know. Havoc12 hasn't backed up his claim by providing combat logs, true. But you haven't proven the contrary either. Personally, I think it's absolutely possible to provide combat logs to prove either point, and even for same boss fight.

The point here is that both ways of thinking are valid. Rating some spells as more important (read: life saving) than others is a totally valid methodology. You try to take that into account by looking at the amount healed - but that's not the whole story, and that's why your analysis won't provide an answer to the issue at hand.

Your question regarding the overheal has already been answered, but let me state that it's really the number of targets hit that you would have to analyse, not the amount overhealed, which makes it pretty difficult with current tools. Anyway, if you were to believe you in your methodology, you would need to take this into account. It think it's a waste of time, though.

We're really deep in simulator territory here, a flat model won't help anybody.

Very nice OP constantius. Useful information for priests. Your Int/Spi numbers look spot on to me.

I disagree that Spell Warding is a useless talent. I prefer it to Divine Fury for my Holy spec. If i'm not casting Gheal why retain Divine Fury?

Lightwell is a strange one. Those raid teams that know how to use it get a lot of benefit from that 1 point. Unfortunantly most players do not even realise what to do with the 'lolwell'.

Renew or not to Renew seems to be a valid and personal preference decision, which adds good variety to cookie cutter builds.

Body and Soul looks a waste to me, but I don't have a lot of Uldar expereince to comment on. It would be excellent lower in the tree so Disc could get it, but as Holy I can't yet see the benefit being worth it.

You are right that in 3.1 Disc priests have less variability in their good builds than Holy.

Gobble gobble.

You might B&S isnt that awesome. But it is. Period. Get it, love it.
Lightwell, its a good talent for only 1 point. I put it at ppl who dont need to move and tank, warlock tank on mimiron. Off tank on Iron Council.

While there isn't a 100% correlation between total healing done and deaths prevented, the two are very closely related. We should take it as axiomatic that increasing the total amount healing is the better choice unless proven otherwise. In other words, if Havoc12 claims that Blessed Resilience is around 1.5% more healing than Empowered Healing but Empowered Healing is still better for preventing deaths, the burden of proof is squarely on his shoulders. There is no need for us to justify the benefit of 1.5% extra healing.

That said, let me address his argument.

Argument a) is based on granularity, and The Not So Evil gave a good explanation for why granularity is a meaningless point in these discussions. The basic argument is "Flash Heal is better on really hurt targets than Circle of Healing, and the really hurt target is in more danger of death." But the counter argument is that the greater healing throughput of group heals could have prevented the target from even getting in that situation in the first place. That enables you to use another round of efficient group heals to keep them up, and other people as well. Rather than granularity we should focus on total throughput.

I don't think argument b) matters much. I don't believe Blizzard designs the encounters "intending" for us to use specific heals in most situations. Their model seems to be, "toss out a bunch of damage and let the healers figure out the optimal way to deal with it". But even if there's a situation where one person takes 15k to the face, you'll still top of the raid faster if you have 3 healers bounce group heals off that healer than if they all cast their version of flash heal on the target. Assume other people in the raid can use the healing from circle of healing, chain heal, beacon of light, and so on.

I confess I don't understand what point you're making with argument c). What is a "repeat per occasion"?

I'm kinda curious as to what simulator's yall are using to come up with these numbers?

And regardless of how exact most of them are, isn't it kinda a matter of semantic's at this point?
Going back through a couple WMO reports, and using RAWR to estimate the actual values, EH is more closer to 10% healing lost on FH/GH/BH (although BH not used as much), which is after taking BR (IE if you took neither, it would be a 13% loss).
So on a WMO report for the night of all bosses (+attempts, short night in ulduar, First 4, + Kolo, and Sarth+3d, Maly):
CoH = 3,426,460
FH = 2,788,577
PoM = 2,390,309
Which = 8,605,346
(which those 3 total about 84% of my total healing)

Had I of taken BR, instead of EH, assuming I did exactly the same behavior in those fights:
CoH = 3,529,538
FH = 2,498,565 (Rawr says its a 10.4% loss)
PoM = 2,462,018
Which = 8,490,121 (and lets say all of the other 16% healing were spells benefiting from BR, so 16% x 3%+ = 0.4% bonus to those)
Which is a 1% (1.4% from 3 main, -4% gain from the other 16%) loss of overall healing.

We could do the same math, on a full night worth of Thorim Hard mode attempts, top 3 abilities = 79% of total healing:
CoH = 6,357,611 / 6,548,339
FH (23% btw) = 4,238,631/ 3,797,813
PoM = 3,669,084 / 3,779,156
14,265,326 vs 14,125,309 = 0.98% difference
And we'll say (there was a couple of Gheal's/Bindings, but less than 1%) all of the other 21% were abilities that gaining a bonus from BR: (21% + 3%)
18,057,374 Total / 18,031,118 (total, assuming the other 21% got the 3% bonus)= 0.1% difference

But what real difference does that make? Does it change gameplay style? Probably.
Does it drastically effect healing potential? Not really
Would taking BR over EH, drastically reduce your effectiveness when having to single target heal? yes
Would it be game breaking, or wipe causing? Probably not.

IMO, the priest class is the best healing class, because of our flexibility. No other healing class can do the variety of tasks, on the level that priests can. Priest's can adapt to any boss fight, and there's never any consequence to bring more of them, over another healer (you can't say that, about trying to bring 5 holy paladin's to a heavy AoE fight).

Personally, I'll stay with EH 5/5 BR 0/3, just because it fits into the gameplay style that I've always used. IMO, just take what benefit's your gameplay the most.