In those big freerolls i wouldnt say waiting for premiums is a good tactic. I mean your not gonna get alot of folds when you raise. So do you really wanna wait 1 hr to get AA then go to the flop with with 5 callers. Sure it works out sometimes, Other times you get it in preflop vs some Ace rag and double. But in general open up your range and play poker. I dont see the point in waiting for premiums when your premiums dont really play well 5 handed post flop.