Quote Originally Posted by Azurarok View Post
The general design split of the four healers is

Reactive Pure - WHM
Reactive Barrier - SGE
Proactive Pure - AST
Proactive Barrier - SCH

The Reactive healers tend to be a safer choice if incoming damage is less predictable, but the Proactive pair are generally the better choice otherwise, and are usually seen as better since this game's fights are so rigidly scripted. Extremes+ enforce the script so heavily that they often don't allow recovery, which Reactive healing excels at.

Moreover, the Proactive healers are still given plenty of tools for Reactive healing that tend to be more than enough to cover the emergency heals needed in skilled hands, so ultimately they kinda end up being able to offer more to the party. Not to mention they're also the ones with raid buffs, which makes everyone's funny numbers look bigger.
I would say that's a good summary of the design split.

One thing I will point out is that, unless you are playing with a very good, very consistent team, you are going to have a not-insignificant amount of unpredictable damage to react to. Having the extra adaptability can be a huge boon in that scenario. But inversely, if everything goes to script, the reactive healers can manage just as well.

As far as damage is concerned, its a balance between higher overall damage potential, and party buffs. Which one is more useful to the team is going to depend on the individual party. But on average, it seems to balance out as far as damage contribution.

They all have their strengths and weaknesses, and situations that they do better or worse in.