I gave away my Gigabyte Z390 build to a friend with Monterey and Batocera installed.
I'm having difficulty parting with my Asus Z370 build because, in my eyes, it was perfect in so many ways. Unfortunately, age and progress caught up to it...
I still have my HP ProDesk 400 G6 on my desk but I haven't booted it up in weeks because my Mac Studio does everything I got it for so much better.
I trashed my Optiplex 3050 tower because felt it was pretty worthless. I still have my Optiplex 3050 SFF that I plan to play around with Proxmox on. I would've liked to do it on a Raspberry Pi, but due to supply chain issues they have been difficult to find and scalpers are selling them for ~$200 now. That's more than these Optiplexes are worth.
I still have my Latitude 3450 laptop and it runs perfectly, but feels very sluggish now with Monterey installed... I guess that's one of the pitfalls of getting accustomed to the extreme snappiness of a modern system...