Well, it's basically linear vs. non-linear motion. With a straight line angle of approach, angular accelleration happens which loads the PP 3 and clubshaft much later in the downswing. With an arc of approach, the PP 3 and clubshaft load is felt much more from the start and longer through the downswing making it suseptable to early release. The basic reason why people with too soft of shafts who miss it left. It's sugnifcance to me is that it's a whole different reason why someone is "quitting" on the shot. It's one thing to say, "You're quitting." and it's another to say "You're quitting BECAUSE you don't feel the Pressure in PP 3 all the way past the ball."