That being said, Khans work lacks polish. You could suggest that his informal presentation style is a plus, or that focusing on producing as much content as possible is more important, but I disagree.
His narration has an erratic cadence and he is often repetitive in a way that corrects or modifies the previous statement rather than building upon it.
His voice is not "radio-friendly", but thats my personal opinion.
The transcripts are poorly laid out and are nearly impossible to scan visually, there only use is for search purposes.
The information architecture is clear and to the point, but it's not oriented to the true beginner. Someone who doesn't already know what the labels mean wont know why they should or shouldn't learn these items.
I hope khan academy invests in polishing some of the great work he has put together so far, I think it would be worth the investment.