i worked at Infinity dealer in Ohio, displayed everything but IRS. I had a few occasions to hear and tweak setup, mostly with CJ Premier electronics and SOTA / Souther / Dynavector Diamond front ends. the towers were maddening to properly integrate…perfect on one recording, abysmal on another….
One customer with a massive LP collection said “ i gave up listening to my collection, now i just listen to whatever LP HP recommend ( the late Harry Pearson of Absolute Sound fame, who i believe took his IRS to the grave…. )