No, it's not the best available. Is it good for getting into raiding in lieu of heroic drops? Sure. The stamina is always nice and while it's not a passive proc, having some control over your avoidance isn't a terrible thing.
I would say the only better available one will come through shadowpan rep. It's stam with a mastery proc. Overall this is a great trinket and should last you a while considering how terrible most tanking trinkets are for us at the moment. There's also a stam with a mastery proc trink that drops from trash but good luck getting one of those to drop.