Starting off, I thought he sounded like he had just taken a bong hit while pinching a loaf. As he went on, I became more and more engaged. Each minute of the speech made me want to hear the next minute, and finally the conclusion. So you have to ask yourself, what makes a good speaker - having polished elocution or relating an engaging story?
Agreed. He's a great example of how successful storytelling can come from charisma and passion as well as diction and articulateness.
There is so much conveyed in his body language. A lot is expressed; surprisingly little made it into words.