He's helpful when there's lots of mobs bashing me during Holy spam, because Choco heals heaps better than WHM in Cleric Stance, and it doesn't cost me a GCD to heal myself, more for Holy, mobs die fast and I'm topped up. Without Choco, doing too many mobs is very risky and MP draining.

So first and foremost, his healing potential needs to be maximized for any class. Even healers, so they dont waste time and MP on healing themselves.

If and when SE add difficult content in which Choco is usable, then I can see the slow debuff being very useful. Currently it doesn't matter what you take once you have the healing, because the content is just trivial in which Choco is usable.