Originally Posted by
Philondra
By "every," do you mean Skeletal Shattering? Because that's the only one that benefits from crit but not mastery, and we've already been over how it's the worst of our major traits. Don't forget that mastery also gives attack power.
Also, (and I could provide you with some math if you want), the amount of Bone Shield charges you save with that .68% parry, and thereby the number of runes you're able to spend on Heart Strike instead of Marrowrend, is one, maybe two at the best. That's also not taking into account that one parry does not necessarily mean one Bone Shield charge saved, because the Bone Shield consumption could already be on cooldown from a different instance of damage.
Edit: In the end, it essentially boils down to this: Do you want slightly smoother damage intake or the unreliable but burst survivability? I suspect the answer will largely boil down to personal preference and how many hots (resto druids) you have in your group.