Got my new i9 iMac installed, up and running.
8 core i9 processor with Radian Pro Vega 48, 512 ssd, 64 G ram (2 sticks so I can go up to 128 if I go crazy).
My external drives are in a Blackmagic Multidock 2 (thunderbolt 2).
A Caldigit TS2 for an extra Ethernet connection for my Metric Halo interface plus some of my numerous USB thingys.
The clean install went pretty smoothly and I've got it down to just a few days of hell.
So far the Logic Pro X benchmarks I've run show that it'll run twice as many virtual instrument tracks (122 vs 58) compared to my old girl (2012 Mac Pro 6 core).
Running nice and cool (I only heard the fan once during some installs and it was barely audible).
I absolutely love the 5k 27 inch but I've been using a dying 24 inch, old Asus ProArt for freakin ever!