WoW is a gear game, and to that there is no real question. As far as healing and DPS goes, there is lenience for sure. When you play a Shaman, your are going to be high in the amount healed because the class actually specializes and excels in this are, especially in raids. Shaman are a bit unchecked too, so they are an amazing class.

I am geared for Kara only, and I still pass on gear in gruul's because my gear is per my spec and play style, that is the most important thing. Know your character. The reason my DPS is so high, is because of my high crit chance! So there are certain armors that may look better, but just do not mesh with my chracter well. I have yet to really play with the teir 4+ gear though. Not entirely interested yet.

Anyways, as far as healing goes, I put it in this order: Circumstance(Raid vs group style)->Class->Talents->Gear

I say this cause my gear may be low, but I can out dps and pvp most other hunters in better gear - unless they have the sands of times ammo. I Strongly attribute this to a solid and class knowledgeable talent build.