Penn & Teller

My favorite performers and all round awesome guy. Hope i get to see them live some day.
But how do people feel about them reveling some of their tricks on stage e.g.
http://www.youtube.com/watch?v=2H81A3bU68k
http://www.youtube.com/watch?v=BPyvAtQYVok&feature=related

and my favourite http://www.youtube.com/watch?v=_qQX-jayixQ&feature=related

I personally feel it enhances their act but given some of the comments on youtube not everyone argees. what do you guys think.
Which is more important? how the trick is done or the illusion?

6th

Penn was greatly influenced by James Randi and has even stated that he loves him most in the world - apart from his family. Penn jumped straight on performing with his focus being that he was performing tricks without the need for making out anything supernatural or paranormal was going on. By showing how some tricks are done he is just underlining that they are after all just tricks.