Haste: Increases the speed at which you cast.
Haste, when balanced, is an incedibly powerful stat for a resto shaman. The goal of stacking haste is two fold, to reduce you GCD and increase your cast speed. Shamans are not as worried about the first, so I'm going to ignore that aspect of it for now. A shaman stacking haste can, if they stack pure haste gems, get an upwards of 35% cast time reductions. Shaman only have one talent that truly plays off of or has an effect dealing with haste.
Tidal Waves- When proc'ed by either Chain Heal or Riptide, this talent provides several effects for Lesser Healing Wave and Healing Wave repectivaly. It increases the bonus healing effects your Healing Wave spell gets by 20%, and a 10% bonus for Lesser Healing Wave. It also increase the cast speed of Healing Wave by 30%.
This talent, while one of the most useful in the Restoration tree, can't be considered a "haste" talent. This talent doesn't provide a set percentage of haste, nor does it have an effect that benefits from haste. It only increases the cast speed of one spell, and only for a short time.
In order to understand the pro's and cons of haste, we need a scenario to use.
Location:Trial of the Crusader
Difficulty:10 man Regular
You are healing along side a holy paladin and a restoration druid. You have a haste rating that increases you cast speed by 30%. Lesser healing wave has a cast time of 1.05 seconds, Healing wave of 1.75 seconds(w/o Tidal Waves) as will Chain Heal.
In order to get such a large amount of haste, several other stats suffered. You only have a buffed mana pool of 23k, along with a 28% crit and 450 Mp5 while casting.
By the time you get to the Icehowl portion of the Northrend Beast encounter, you are at 30% mana and have already used Mana Tide Totem. After his second crash, you don't have enough mana to cast any spells and the tank dies while the other two healers are frozen in his breath.
From this scenario, you can see the downfall of an unbalanced haste stack.
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