I used to be a full stamina bear, but after giving agility a fair chance now I must say I am impressed. I still use my heroic Vial of Stolen Memories because it has such a beautiful use effect for us bears, I basically become immune to physical hits when I use it due to dodge.
So I say dump stamina, it ain't worth it. As cool as you'd look with all that HP the extra dodge helps alot (Heroic Zon'ozz says 'hi'.)