I'd rather have a lock with a teleporter for the raid than a mage in the tornado phase, but oh well. (We actually raid with 2 locks in our 10 man, so yay on Iron Qon )
On the DPS side I could keep up fine though.
And wait until you hit a boss like Council heroic, where you'll notice quite painfully how much you lack in personal cooldowns and such. Getting the really painful frost thing once is fine, since you can block a decent while. Get it a second time and you're likely to drop dead though