I have no clue why everyone had those in their deck. I guess they just wanted to show off "HAY! I HAZ SOG!". Since they really aren't that OP.
They destroy decks with low damage output, but other than that, all they do is provide a small amount of stalling. *Most* decks, especially some of the ones I saw posted, would have been better off making the draws less random (and therefore making the deck more consistent) by taking the sogs out. 1-3 SoG *usually* has no profound effect. It starts getting helpful once you get 4-6 out, but that's late game, and by then most of the tourny decks I've seen would have either won or lost already.
Anything less than a pure damage rush will be slowed significantly, not just a small amount. Weak damage decks, like morning star, are completely destroyed. In the time the deck gains, it can get to its main purpose. With a bit of creature control, you can lower your opponent's damage below your healing, and then kill him leisure. If your control is strong, you can even stop a damage rush.
More importantly, it combines very well with other forms of defense. Once I got set up, immortal creatures and firebolts were the only things that could kill me, if my opponent didn't have either, I could just rewind everything and be invulnerable. Heavy permanent control could keep me from setting up in the first place, but few decks take that much without pulvy, which was unupped.
Other decks were based on fire bolts, where five turns of quanta building is a massive advantage.
It isn't that strong -- if you take it unassisted and compare it to dragons. Throw in turtle shield or dusk mantle and it doubles in power. Zap a dragon or two, and your opponent won't even be able to lower your life.
You do need to use it properly for it to be incredible, but is. It's also a decent card to throw in nearly any deck, though not always the best.
