Started playing my MW Monk in dungeons and I think I've used Effuse maybe once or twice the entire time. I just don't see the point in it when Viv is so much better.
Viv costs about twice as much but heals for about twice as much AND it heals 3 targets... Sooo why should I ever use Effuse? Especially in group where multiple people are usually getting hit.
So far the only use I found for it is starting SM heal on a specific target that is taking low damage...