I thought so, but i switched a few pieces last two weeks and i'm almost BiS gear, and still i found that the best is gemming crit. And i mean, i didn't see one "good" warrior doing that, most of them switched most gems to mastery. That brings me to think that i'm doing it wrong, not all the rest lol
But then why did you switch your gems in the first place?
And i mean, even 1st ranked warriors are gemming mastery, and according to SimC that's a pretty significant loss.
Anyways, the content is not challenging but the only thing that keeps me interested is this, otherwise i wouldn't even show up to raid