At current gear levels, the value of expertise and hit is basically > all, in order to keep your active mitigation rolling by means of every possibly rage generating attack landing. Whether that remains the case in higher tiers and gear levels, we won't know. Basically, hit 7.5% > expertise 15% > mastery > parry > dodge, and generally some hybrid stam gems[deleted]. Stam still does have a lot of value but it's more on par with other stats than in previous expansions. Read the guide though.