This ends up being the same question that new players keep asking that has spanned multiple expansions. The war between throughput and regeneration continues to be debated. Really, though, there isn't much to discuss because you can't really compare the two on the same scale.
Throughput refers to the strength and impact your spells make. Intellect, critical strike rating, mastery and haste affect that to some degree, depending on your class. Regeneration is largely about your mana pool and the rate at which you gain mana back. Without mana, no spells can be cast. Intellect and spirit are the main stats here. They both affect different parts of your game, and I hesitate whenever I'm asked to pit the two against each other.
There are two routes to victory when deciding on a raid composition strategy:
- Sacrifice a healer slot in favor of a DPS player for additional damage. This means bosses will die faster, meaning your healers don't have to heal as much or as long. That's about five to six healers in a 25-player raid.
- Go for the endurance race and pull in an extra healer in order to run a controlled strategy that involves gradually chipping away at boss health. This tends to involve seven to eight healers in a 25-player raid.
The case for throughput
The boss you're taking on has a tight enrage timer. Your DPS is going to have to play loose with a variety of environmental mechanics and will be taking extra damage. They're largely doing it to try to squeeze a little extra DPS. That means an extra tick of fire here or getting hit by an AoE there. No big deal. As healers, we prefer players who minimize unnecessary damage. As realistic healers, we know that isn't always the case. We'd be delusional in expecting crisp and perfect play, unless you're in a top-ranking world guild.
Anything that makes your healing hit harder and faster is appealing. If you can keep a player alive with one spell instead of two, you can use that second cast on someone else who is caught in a similarly bad situation. It also means you need to heal smarter in the long run and pay attention to your addons if they have an incoming heal indicator -- no sense waste healing spells on someone who is about to get some (which you shouldn't be doing, no matter which way you lean).
The case for regeneration
You're learning the ropes of an encounter. The enrage timer is a non-issue. This is the kind of fight in which you need to stretch out your mana. The DPS players you have with you are slightly below average. When it comes to endurance healing, this is the favored approach, since it allows you to last longer. Additional intellect and spirit are weighted more compared to other secondary stats.
Okay, to be fair, intellect is always going to be the must-have stat, no matter what.
You might even want to consider talents that provide additional ways for you to get mana back, like Telluric Currents. Personally, I've debated grabbing Veiled Shadows on some fights. Having a Shadowfiend a full minute earlier when I'm gasping for mana would be a life-saver. My guild is taking shots at heroic Maloriak. After exhausting all my mana cooldowns and potions, I find that I'm about 30 seconds away from having a Shadowfiend available when I have nothing left in the tank. So I'm going to modify my holy spec to incorporate it, to see if it'll generate positive results.
The next time you're placed in a situation comparing throughput and regeneration, take a minute and say that the two can't really be compared since they serve different aspects of your character. If secondary stats (such as mastery, haste or critical strike) are the ones being compared, that's a different story that has different answers based on your class.
Vive la difference
Speaking of secondary stats, are you in a guild where you are not the lone healer representative of your class? For example, you might be one of two holy paladins. I have a question for you: Do you deviate slightly in your spec or reforges? I want to know how many healers match each other spec for spec and reforge for reforge. It seems that healers have been conditioned to favor a specific spec and stat allocation. In guilds where there are more of your class, would it not make sense to have a slight variety in playstyle?
I have two holy paladins in my guild. One has expressed interest in favoring critical strike and mastery (which is getting modified in patch 4.1), while the other is opting for a haste approach. One paladin would be perfect for exclusively tank healing, while the other paladin is a healing turret in plate going wild on players within the raid. Seems like an interesting idea, and I'm curious to see how it'll play out after the patch. I'm not sure if that same duality approach can be applied to other classes.
Let me know in the comments if this is a practice your raid group does and if your group engages in 10- or 25-player content. I'm curious to see what your thoughts are on the matter.
Need advice on working with the healers in your guild? Raid Rx has you covered. Send your questions about raid healing to firstname.lastname@example.org. For less healer-centric raiding advice, visit Ready Check for advanced tactics and advice for the endgame raider.