@wvonm, I wrote a lengthy review on this several weeks ago, but I think Penguin is blocking it because it's a negative review. The trick is easy to do but it is NOT impromptu. You have to know where you'll be performing it. Sometimes that's easy, but it is REQUIRED. You cannot just walk into a room, snatch a deck from old Bob's poker night, and bang, miracles.
But that's not the biggest problem to me. Unless your audience consists of folks who've had a recent run-in with a short-term memory eraser, this thing simply won't fly. There's no amount of stage presence, no amount of audience control that's gonna save you when your marks realize you're showing them something far different than what they just saw on the table in front of them. The method, without giving anything away, assumes a level of blissful unawareness that most folks, even polite ones, just don't possess.
And God help you, what if the kind soul you ask to borrow a deck from hands you a different one than the one (or ones) you're prepared for? You're out to sea in a sieve.
So the short answer is, technically, this is very easy to perform. But there's just too much wrong with it to try. Too many holes. Dani has *many* better tricks in his arsenal.