At level 70 if you could stay block capped with them, the Tundra shoulders are a minor upgrade to the T5 and a clear winner over the ZA shoulder. Don't forget the extra armor when looking at the pieces.
Assuming 2 +15 stam gems the ZA shoulders have 17 stamina, 21 BR vs 7 BV, 4 def, 25 dodge, and 109 armor.
Now that we are leveling the BR on the ZA shoulders will likely keep them our prefer choice.
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Majiben
If we wanted Ret to be a joke, we would have just left the tree as it was, and maybe kicked it a little for good measure. -GC