this is my favorit AA in existance. It will heal everyone with HoT at no agro expense to you.
this can be used when everyone is getting hit (aoe or just lots of adds) or it can add the extra healing power needed to keep a tank alive just long enough to cast CHeal, or perhaps just heal when you OOM and have no other way to do it.
basically it is free healing with no agro; it can never hurt to have and with AA can be used farily often. I have even done low level camps and made a game out of healing by only using celesstrail regain, divine arbtration, and healing ward so I can use mana only for nuking.