Verraise drains RDM's mp very quickly so it's not quite as infinite, but their being able to rapid fire it sure can save a wipe in the right hands, and I honestly really appreciate it in prog parties since it lets healers focus on topping up the rest of the party and we can actually try the next mech.

Slight tangent but I kinda think WHM could use a similar advantage over the other healers by making Thin Air also grant instant casts.