[Ringer]

From a practical standpoint, what can the D-Plane concept do for you that 1-L #5 through #17 cannot? Also, on what other basis -- practical or theoretical -- is it superior?

For one thing it explains Hogan's ball position chart much more clearly. Where does it say in 1-L 5-17 that one should open their stance as the low point gets further ahead of the ball? One must infer that information themselves based on other statements.

The D-Plane is there to help discern true path as opposed to plane line for the real resultant path of the clubhead during impact. It's been a while since I've brushed up on my TGM but I pulled it out for the sections you cited and cannot find any reference to true path. Is there another location I should be looking besides 1-L 5-17?

Also, something else D-Plane explains is that straighter shots come from higher lofted clubs than longer clubs. That's something I explained in the first video cited but I do not see any such mention by Homer.