As an update;
I've been using my i9 iMac since July and it has been a dream come true for me.
More than twice as capable than my 2012 Cheese Grater 6 core/48G ram.
The 27 inch 5k display with the Pro Vega 48 graphics still catches me staring at high rez images just for the heck of it.
A while back I was doing some articulation template (a Logic thing) testing and I had 500 software instrument tracks open in Logic.
The fan is super quiet so I never know when it's running.
Couldn't be happier!