Seeing im running 4 shamans and a druid, i have a very high base to crit. Now im looking at what gems i should start putting in my gear and i was wondering is it possible to have too much crit rating before you get a dismal return. For example +def gets to a point where you become uncrittable, but it still gives you a little bit of avoidance for every bit of extra def rating you add on after that. Is it the same with spell crit in any way?