In my limited experience, resto Druid makes a hella healing intensive healer, you can't just sit back and cast a few spells, you have to help mitigate damage from your target with roots, definitely have to kite like a mad man, and you have thorns which is a GREAT weapon against melee... I think that the ability to stealth as a healer brings yet another great weapon in terms of utility... Like everyone has stated already, weakest healer of the four, but in my opinion, you shouldn't let that deter you from playing the class. It really is a lot of fun!!