The Historic Spec pots are CTS from what I understand.
Selling a basic, properly designed OEM (as in what Fender uses on everything they produce OEM) component, and calling it something special - gotta love those folks in Gibson's marketing division...
My experience w/ Gibson pots is the same as many others here, and it's a constant source of amazement to me when I, for example just today, wire up a $4K CS instrument with basic CTS pots to realize an audible improvement.
...not to bash Gibson, just sharing my, well...amazement.
yeah, it should be the same wide open. that points to the difference in resistance being enough to hear, i suppose.