I've never been great in comparing stats. And particularly since my main character is a druid, the concept of min-maxing doesn't quite fit in many cases. Of course it's easy to go for the usual +heal/+int/+sta and upgrade when possible. But "mana/5 seconds" remains bit of a mystery in comparison to other stats. Some people go nuts for it, some people look down to it. At the moment I have +50 mp5, so I suppose it's nice to get 6000 mana from it in a 10 minute fight, particularly since I have a tendency to try to heal throughout the fight without long breaks.

But how would you compare it to other stats? How many points of +heal would you be willing to give up for 5 mana / 5 (or whatever figure you want to use)? How does Blizzard value it in item formulas? Does it have any purpose outside raid environment? Are there any "optimal figures" that I should aim for? (right now I have around +680 heal and said 50 mp5)

The stat isn't discussed a lot I guess. Let's face it, there's not much that you can raise your e-peen by saying "dudes, I have 100 mp/5". It's already a bit silly how healers brag about their +heal numbers.

The short answer is "it's not easy to compare them". While +healing causes your heals to heal for more, increasing your HPS (useful in only a few fights where HPS matters) and/or increasing your HPM, it's quite likely to be wasted, and healing the tank for 1100 instead of 1000 may end up saving someone else mana instead of you, so in a vacuum it's very difficult to quantify. Regen is fairly straightforward: more regen = more mana = more endurance, and as another example of how wacky healer itemization is it may even allow you to uprank to a spell that costs more mana simply because you can sustain it. But comparing the two is... uh... hard. They serve the same aim, but some fights favor one or the other, and other favor a mix. (Even for Maexxna you only need a couple of healers of each type with high +healing.)

So the answer is to have different types of healers. Me, I try (given my limited DKP pool) to focus on regen-heavy gear; others focus on +healing.

If you have a healing budget and have enough +healing to go down a rank - that will almost always save you more mana and increase efficacy faster than you could get from mp5.

If you are a shaman however - mp5 is pretty damn good in general.

Its hard to tell, and I havent really had the stamina to go in-depth in the raw maths of MP5 vs +healing and spirit, but I'll share my experience and how I think the different stats "feel", with emphazis on MP5 vs. the others.

Generally, in my experience, you either have the choice of some +healing and spirit, or alot +healing and MP5. Atm in my "MP5" gear I have +750 healing (I like to say +853, because thats what it is with added talents (Spiritual Guidance), but I'll stick to the raw healing from my gear) and 117 MP5. In that gear I also get +100 spirit (which is fairly weak for a priest).

So basically I have +750 healing, 117 MP5 and "fairly low spirit". The way I picked my gear was to look purely at the MP5, and I found that it actually gave quite a fair amount of +healing aswell, and this is how most MP5 items are.

In fights (buffed with normal buffs) I usually regen 75 mana every 2 seconds while casting, while having 140 every 2 seconds outside the 5 second rule. Priests in gear composed mostly of Transcendence usually has 50 every 2 inside the rule and 140 aswell outside. We also have a priest who goes purely for spirit in raids, which has about 70 every 2 sec inside the rule, but he has 170 outside the rule. (It's worth noting that this priest only has +450 healing with that amazing regen).

So basically, while MP5 gives you amazing regen while casting, and on top of that it gives you some major +healing its slightly worse than the pure spirit healer when you're not casting. (You'll find that you're not casting alot more than you'd think if you're cancelling heals properly).

The main drawback with MP5 is that you will lack heavily in the spirit department, which in turn, makes you benefit significantly less than other priests from Innervate, but in general I'm very happy with my gear build.

Also, it's worth to note that if you're a druid or a shaman (I wont comment on Paladins as they usually never run oom anyway due to Illumination) you wont be getting much innervates, which would make MP5 alot better for you than it is for me).

Difficult to compare, lots of ways to think about it, lots of class variation...but there is one thought I've always maintained:

There are plenty of consumables to extend your healing stamina; there are virtually none to extend your HPS.

As a Priest or Druid, two of the biggest factors in determining whether or not you should stack +healing or mp5 are whether or not you have Blessing of Wisdom and Judgement of Wisdom.

Because we can just simply stop healing the mt and run up to the giant aoe'ing boss mob and melee to regen. Sorry, this just isnt viable for druids. Priests can wand, certainly, but there should be no time that your priests are oom with enough druids around. JoW is virtually useless to alliance healers unless you're running a healing rotation - which none of the fights in this game truly necessitate.

Ive reached a point with my gear where I can't go oom unless I actually try to, or everyone else is massively slacking off.

Imo, you gear yourself to a fight depending on how the fight mechanics work. Somewhere like the Twin Emps - you want as much regen as possible, because it is an endurance fight. Something less time intensive- you want +healing because you need to push more hp/s. There's two kinds of healing fights in this game - 1. How long can you keep the tank up, and increasingly #2( with all the enrage mechanics in every fight now- which is REALLY getting old) - Can you deal with a short intense fight with high damage incoming?

Since I've been raiding I've attempted to find a balance and maintain the highest spirit, Mana per 5, and +healing. While not sacrificing anything. So far with, with my current gear anyways, I have managed to come up with:

(Unbuffed stats)

243 Stamina = 3647 HP
366 Intellect = 6586 MP
285 Spirit = 84.25 mana per tick(25.275 mana per tick while casting)
65 Mana Per 5
+822 Healing

Currently I'm trying to obtain a combo with higher spirit for less intel but it is hard to do. As spirit with spiritual guidance alson increases +healing :)

Funny, I started using this the other day (perhaps on the advice of this forum, I don't remember). So far I'm liking it, and it means I don't have to deal with the hilariously broken old version of Spirit Versus Intellect (whose author appears to have lost his mind, since every version but the first one is an enormous pile of crap).

Bit of a derail, but the two things I've noticed are that if you enter combat by casting a spell the addon doesn't catch it (not that I care about my FSR% while farming, but someone might care about whether they're gaining or losing mana, who knows), and that it doesn't account for Blue Dragon at all (or presumably similar abilities like Innervate? wasn't paying attention to that).

Heh, glad you found it, and I hope you find it useful... I'm a warlock, so I don't actually use it myself, which means stuff might escape my attention sometimes. As far as stuff like Innervate and Blue Dragon, it definitely doesn't watch for these, as I was just making a simple mod for a friend initially, with no grand designs for the ultimate mana usage mod in mind.

Pretty much the only thing it watches for is whether you gain or lose mana, so unfortunately there's no way for it to tell whether you've just been innervated, had your dragon deck proc, or if you've potted or are under the effects of BoW, JoW, Mana Spring, Mana Tide, what have you. But, since those are sort of standard elements of your play anyway, I figure it's good to see them in the total mana gained / lost anyway.

Edit:
Basically, it's to show you how much each stat was worth to you in the last fight; if the ratio matches the ratio on your gear, you've regenned optimally. Whether you want to adjust your playstyle to your gear, or your gear to your playstyle, FSRT is intended to serve as a useful metric.

Also you might notice the fsr timer trigger when you change gear, since it judges whether you've cast a spell solely by mana lost, since that's the only time it ever gets activated anyway.

Also as a shameless self plug you should check out my other mods on curse to see if you like those too. :)

Yeah, like I said I've been using SvI for the same purpose for awhile now. But SvI is set to autodetect talents as of about 1.9 (which means that for some reason it thinks I have 5/5 MS when I'm 21/30), and for reasons that are frankly beyond me the new version not only has Titan integration for no good reason, but the author managed to break the mana regen formulas.

If I get bored enough I'll see how hard it'd be to hack Blue Dragon/Innervate detection into there and let you know the results, since it'd be nice to see how much of a difference Blue Dragon makes in my FSR%. Maybe there's some other event that fires on successful spell cast or something?