» Thu Dec 08, 2011 3:59 pm
The unlock in Alteration requires 3 perk points to fully unlock. It gives you x3 armor bonus from Alteration's armor spells if you wear no real armor. The best spell is Ebonyflesh, which adds 100 armor: *3 is 300. This spell requires significant magicka to cast, and it only lasts 1 minute.
Contrast: Light armor. Which can easily give an armor rating over 300 if you spend 3 perk points on it, while costing no magicka at all and which doesn't "wear off" mid battle.
I don't see how there's really any debate at all, if you're into Enchanting. Physical armor can be made to have the same benefits as robes, as well as substantial passive protection. Mage armor is a costly, time-limited, active defense.