Originally Posted by
Dracodraco
For boomkin or resto :s.
Assuming resto, as else you'd probably be wanting crit+spirit gems if you even wanted to unlock that bonus... On the other hand, if you're resto, you'd want pure spirit gems instead of a mixture. Uh. Not really sure what I'm dealing with here.
Regardless, for resto, int and mastery is pretty much the same, except int provides spellpower, which has a scaling component with most spells, while mastery is a flat modifier - int also adds a tiny amount of crit. Usually, you can go by the rule of thumb that mastery:int is 3:1 in terms of power (so 3 mastery is equal to 1 int). This means that in a socket where you'd have the choise between mastery and int, you'd always pick int, as they only come in a 2:1 ratio (60 int for 120 mastery, instead of 60 int for 180 mastery).
But if you're resto, you REALLY want to put pure spirit gems in there.