I am completely inept (it's true, I might as well have stumps for hands), and while I've purchased a number of downloads and DVDs from Theory 11, Witness was the first trick I showed to anyone. In this case, it was a friend who knew I was trying some card magic and he wanted to see a card trick. I was nervous and I made what I thought were two or three obvious blunders in presenting the trick--but when the final reveal was made, he was completely shocked. I thought he was being kind, but no, he was completely shocked. Shocked like the people in the trailer.
I then did a much smoother job of showing him A Poker Player's Picnic from the Royal Road to Card Magic; he thought it was pleasant but said that if he thought about it for a few minutes he could probably figure out how I did it. Then he asked me to do Witness again.
So I would say I got my money's worth. I'm going to practice it a ton more, though--if only so I can do it with more confidence and style, and feel that I'm doing it justice when I perform it.