Arcane DPS lower than Elemental Shaman?

[Bollwerk]

So my 4 caster toons are all mostly maxed out with LFR / Valor gear and I'm finding that my Arcane Mage's DPS is always less than my Elemental Shaman's on single target (Boss) fights.
It's not lower by a lot, but I keep seeing other "real" Arcane Mages in LFR doing WAY more DPS than my mage, so I'm wondering if I'm doing something wrong.
My macros are essentially straight from Mercurio's "Cataclysm macros at 85".
Any ideas on how to improve my DPS or should I try Fire or Frost?
(although I understand those are harder to do macros for and get good DPS)

Arcane Seqence Macro
/stopmacro [channeling]
/castsequence reset=6 Arcane Blast,Arcane Blast,Arcane Blast,Arcane Barrage

Arcane Proc Macro
/stopmacro [channeling]
/castsequence reset=6 Arcane Blast,Arcane Missiles
/cast Presence of Mind
/cast Mirror Image
/use Mana Gem
/cast Arcane Power

For reference:

http://us.battle.net/wow/en/characte...iriel/advanced

http://us.battle.net/wow/en/characte...uriel/advanced