I'm going to try to clarify my thoughts about the release bit more so i don't sound so much like a cook-stick.
A number of years ago, I was talking to Alistair Cochran about creating a universal framework of measurement that you could use to plot any swing, no matter the skill level of the player, that would clearly identify similarities/differences and thus establish common denominators among good ball strikers. One of the obvious goals would be to completely eradicate aesthetic values....or at least redefine true aesthetic value, ie, Nicklaus and Trevino are both beautiful as this measurement defines beauty.
Cochran was not impressed, but I was impressed with myself. Anyway, it kinda goes like this:
If done in 2D, and sketched on a piece of paper, the paper reresents the plane the longitudinal cg of the club through the impact zone. That is the basic reference plane. Not the shaft plane at address, not the swing plane half way down. So you are looking perpendicular to the impact plane of the LCG.
On that plane I would choose these reference points: FCCoG, Left wrist hinge, and Body CoG. Obviously, there are more moving parts, hinges, levers between these points....but they are the big boys.
For these points I would plot lateral displacement, curvilinear motion and rotational motion, ie, these points move and pure rotational motion around these points is curvilinear, etc. Would help define hip turn vs slide, and clubhead elipitical paths.
From this entire frame of reference I could better understand the true behavior of every swing. Examples:
A golfing machiner dragging the handle would show up quite vividly.
A recreational golfer casting would show up.
The handle traveling up the plane (up and left viewed from a different plane) as the FCCoG swings out to the ball would be clear.
Trevino, Hogan and Nicklaus would have very similar signatures in this context, contrasted against high handicapers.
So, this is where my reference point of left wrist is substituted for cp on grip. Both points would move "almost" the same, but I think the plot of the center of the grip would be slightly more muddled because I think the left wrist defines the coupling of the two "systems" better. IMHP