They seem to be quite demanding as regards endorsements. I just read an interview with Kirk Hammett in a German Guitar & Bass mag and he said that Metallica had been in intenisve discussions with Gibson re a Metallica signature guitar line but that Gibson's demands (When, where and how often will these be played? Will you be playing other guitars too?") were so exacting, Metallica lost nerve and stuck with ESP "who are much more uncomplicated".
That kind of sounds like Gibson.
Uwe