Thanks, Steven .........for the wealth of information you have published over the years that most of us who read you would never have attained. There are many here who have great admiration and respect for your gunmaking abilities, myself included. But, as for me, not so much your lack of forbearance and ability to disagree without insulting.
Don has never claimed to have broken any new ground, AFAIK, concerning gun handling characteristics. What he has done, with his "whirly gig", is quantified handling characteristics and created a data base. When used properly it can help us mere mortals who like the way a particular gun handles, and who need some guidance in being able to find another that handles nearly the same way. I know now, because of Don's patience in helping me understand it, that a gun does not have to weigh the same, have the same length barrels, or even be the same gauge to do so. A .410 can handle almost identically to a 12 ga. game gun ...... if the weight is in the right place(s).
No thanks, Steven ..........for your condescension. It does not become a man of your great talent and knowledge.
And, FWIW, I'm another who doesn't worship at the MM altar.
SRH