"I just find myself wondering to what extent the YC interview gives the startup team a chance to get their initial burst of "stuff" out before starting to take them off on tangents."
I believe Paul answered this in a comment on the thread.
I don't see the need for the start up to present anything in what is an interview, not a presentation. As Paul is conducting a ten minute interview based on the application, why would he have to give any time for the start-up team's prepared presentation? Its only ten minutes, and its him asking questions of the start-up to see how well they can answer the questions that arose from their application.
I believe Paul answered this in a comment on the thread.
I don't see the need for the start up to present anything in what is an interview, not a presentation. As Paul is conducting a ten minute interview based on the application, why would he have to give any time for the start-up team's prepared presentation? Its only ten minutes, and its him asking questions of the start-up to see how well they can answer the questions that arose from their application.