Great effect, old idea. This is another one of those effects where if you were able to see the full trailer you would go "OH". Now don't get me wrong. It is still great, but I just feel a bit eh...
You really do only use 4 cards and the spectators are amazed.
But this is relatively an easy ungimmicked effect if you chose.
So 3 stars overall. IMO a little over priced as well should have been -15 - Would recommend for beginners.