Quote from steve_man »
I've had some pretty amazing experiences with this where I've gotten 14+ mana worth of creatures for only 5 mana. You should always be trading up when casting this spell in the right shell, and the blowout risk is much, much lower than something like Show and Tell since your opponent's copy resolves first.
I can second this. This card is very good and I don't consider it filler at all. It is very unique and cool to play with!