The PPT merely introduces the talking points. That's done by design, to create more of a discussion format than a lecture. And yeah, a lot of it depends upon the classroom instructor's ability to take those points and turn them into useful - and memorable - information.

Keep in mind also the varying experience levels in a given HPDE group, and the aforementioned differences of opinion and perspective. And the desire to not overload anyone (better to have 10 key points that people will remember 7 of, than 20 key points that people will remember 10 of.) Also the fact that the most important learning takes place in the car on the track with the right seat instructor.

Having done classroom more than a few times myself, I can tell you that it's a lot harder to teach "just enough but not too much and not too little" than it seems like it would be.

As for "in depth" - as I said, NASA-MA (and Unkefer specifically) are some of the best in the business.