Mage Armor or Frost?

[Shnuggles]

So I have one main question.
I've been using Mage Armor as Arcane, all the time, never use Frost Armor.
BUT!!!! I just saw that you only use Mage Armor for multi-target fights, and you use Frost Armor for single target fights.
Is this true? And if so... why? I thought Arcane's DPS was all dependent on our mana and Mastery?

[Ghostlawbster]

There's a thread by Komma that goes somewhat indepth into some theory crafting around it. However there may be limitations in it, but here's the link http://altered-time.com/forum/viewtopic.php?f=3&t=313" target="_blank