Not surprising that an ART9 would completely crush a Grado MCZ. MCZ was noticeably inferior to Grado TLZ and XTZ, 30 years ago, to my ears in my system, of course. (I don't mean to sound snotty, but maybe I do. Sorry.) I still have the TLZ, but my sample seems to have lost "something" after 30 years in storage; I brought it out last year for a trial re-run. It probably would benefit from some patience, while the suspension loosens up, if it will ever loosen up. I've got an ART7, still in the box.