Critical Strike Rating: Increases the chance for your spells to critically hit.
This is an amazing stat for shamans, a fact some don't readily agree with. The purpose of this posts and several to follow is to explain stat choices and how they actually benefit you are a healer.
There are a slew of talents in the Restoration tree that deal directly with crit, the following are just the ones that provide a proc/buff/additional heal from critical heals.
Improved Water Shield-This talent is a staple in shaman mana conservation and regeneration. It allows the amount of mana returned from a destroyed Water Shield orb to be returned on a critical heal without destroying the orb. With a high amount of crit, this talent can proc on one out of every two heals cast depending on the spell.
Ancestral Healing-This talent is a shamans version of a disc priest bubble, albeit a comparatively weak one. In essence, this gives a base, 10% damage reduction on targets hit with a critical heal. In several 10m settings, it is possible for a crit geared shaman to have this effect on all members of the raid and one time, though this is not an often occurrence.
Ancestral Awakening-This talent is for all intensive purposes, an additional heal costing no mana after a critical heal. Consider this, a Lesser Healing Wave crits a raid member for an 8000 crit- this talent will provide an additional 2400 healing for no mana on the lowest % HP raid member.
So these talents deal directly with the benefits of having a large amount of crit, but the Restoration tree provides multiple talents that flat out increase our crit %.
Tidal Mastery-A flat 5% crit increase on all spells. A guarantee in all Restoration shamans.
Blessing of the Eternals-A flat 4% crit increase on all spells. Also as an added bonus an addition to Earthliving procs which is always helpful. This is a guarantee in a healing shamans build also.
Thundering Strikes-Though not actually in the Restoration tree, this is a talent taken by all Restoration shamans. Another flat 5% crit increase to all spells.
With so many talents effecting, and effected by crit, I'm always surprised that so many people don't know the true value of crit. Critical heals provide a restoration shaman with a mana return, damage mitigation and an additional free heal for 30% of the original crit. Would I say that crit is the most important stat for a resto shaman? I couldn't really say that because all healers have a different style of playing. I know some shamans the never use riptide but still are able to heal effectively. I know some that stack so much haste they have a Lesser Healing Wave that is under 1 second. Some stack so much Mp5 and Int that it is almost impossible for them to go below 80% mana. These are all different ways of capitalizing on the versatility of the restoration shaman, and all have their merit(except haste stacker's without Mp5 trinkets, faster spells means "SHIT no mana!" comes sooner).
Critical strike is the most prevalent, and in my opinion ignored stat for resto shamans. With the raid make-up I usually run with, I have nearly a 45% critical strike chance. This is an incredibly high amount, and I only wish I could get more. I know their are benefits to Haste, Mp5 and even Int stacking, but flat out Crit is usually how I go, because with so many talents that increase it and benefit from it, why wouldn't you want a lot?
This wall o' text brought to you by: "CRITICAL HEAL MUTHA FUCKER!!!!!!!" Also, the Shamans Association for voice-box replacement.