Armor has almost no effect on your spellcasting.
Benefit(s): You don’t have to spend a swift action to gain the reduction to arcane spell failure chance from Arcane Armor Mastery. Furthermore, you reduce your total arcane spell failure reduction for any armor you are proficient with by 30%.
Mythic Options: The Missing Core Feats. © 2013, Owen K.C. Stephens; Author: Owen K.C. Stephens