I literally just lost to it. The tough part is that it's quite hard to counter too. They run double Ice Block, have lots of tradeable minions to swallow up Dirty Rat or Mutanus hits, plus get the card draw. I would've won had my Zephrys gave me something to destroy a secret instead of lethal damage (ggrrrrr) but still.
This and APM mage are both pretty unfun decks to play against. Almost no one plays secret mage anymore because these are so OP. And even though things like Questline Hunter and Warrior are more popular, it still doesn't feel as bad to lose to IMO