Same here. My first lvl 70 back in BC was a mage and I played Arcane in TBC, Wrath and Cata. Loved it. MoP? That rune ticks me off... Mana management is fun, I really think so, but the rune is just horrible. I with Blizzard could go back to the style where you dumped your mana during bursts. Mastery prevents that a bit, but if Arcane Power got changed to "gives you the full benefit of mastery regardless of mana level for the duration", it would work wonders.