What does Heart of the Wild actually do for Boomkins?
Heart of the Wild does the following for Balance druids:
- All your healing spells do 50% more healing and cost no mana.
- In cat form you gain 100% more agility.
- In bear form you gain 50% more agility and 100% more armor.
You can see the healing changes in the spell description on Wowhead (effects #1 and #2), the other effects are not directly visible. I used the spell and compared the values for cat and bear forms myself.