Brad Henderson wrote:What highly regarded, powerful magic effects position the key move at the moment of the magic?
There are many examples of this ... When one billiard ball becomes two, when a card vanishes at the fingertips, when a pair of gloves transforms into a dove, etc.
All classical, powerful and very magical effects. Others would include the vanishing birdcage, cane to silks, and that trick where a pot of flowers instantly and visibly vanishes from a table top.
These are all from the world of stage magic but close-up has many examples also. I will never forget the first time I saw Ricky Jay perform his Queen's Coterie. I was awed by the sequence where the four queens are produced via the Piet Forton pop out move. I had no idea what he was doing and it was beautiful. Although this is a prime example of the move being simultaneous to the magic, to my eyes it was just that - magic.
All of these have one thing in common, they have to be done at the proper speed to be deceptive. Not to say that in all cases they have to be done fast, but they certainly could not be done super slowly without disclosing the method. I would think the same would be true of Circuit.
An example of an effect where the key move is positioned at the moment of the magic, which can be done as slowly as you like, would be the vanish or change of a card utilizing the Elmsley count.