Besides better organization of my living room the only gear I have seriously heard that was just so spectacularly better than current is perhaps the CAT preamp and Vandersteen amp. Yes, they make an amp.
Besides that I’ve heard incremental differences in very expensive gear but these two are the only bits of gear I heard that actually made me wish I was part of the 1%.
Everything else compared to my Luxman integrated was just a small improvement for tons of cash or worse. Those two bits of gear though are amazing.