The real problem with Frostbite is that, unlike Sundial, it's a one-time effect rather than an ongoing one. That means that, unlike Sundial, you can play it and then, in the same turn, play, say, a Sky Dragon and a Twin Universe, and lay on the 24-points-per-round beatdown while all of your opponent's creatures are frozen solid. Your opponent MIGHT have another useful creature in his hand, but that's unlikely.
Essence
The Heterodox