Hi I know you hate this, but here goes. I'm a Prot Warrior with Fury as my offspec (my armory currently shows my fury set).
Given my gear and my previous experience as Fury I've stayed Fury as my dual spec, but is Arms that much better than it's worth changing? FWIW my only 213 2 handers are 2 'geddons, I don't have any good Maces or Axes.
I'm comfortable with Fury even if some find it boring...
Oh and my helm options are Obsidian and 7.5. Right now I use Obsidian + the heroic ring to get to the (new) Expertise cap. I wish I could use the Valor ring but I never got Razuvious belt or whatever so I don't have that option.