Aside from the GPU mess, the 2013 was a nice machine, basically a proto-Mac Studio. Aside from software, the only thing that pushed me off my D300/64GB/12-core as an everyday desktop + front-end machine is the fact that there's no economically sensible way to get 4K video at 120 Hz given that an eGPU enclosure + a decent AMD GPU would cost as much as a Mac mini, so I'm slumming it in Windows for a few months until the smoke clears from the next Mac Studio announcement.

At which point I'll decide whether to replace my Mac Pro with a Mac Studio or a Linux workstation; honestly, I'm about 60/40 leaning towards Linux at this point, in which case I'd also buy a lower-end Mac, probably a MacBook Air.

I'm in the Linux desktop / Mac laptop camp, and it works well for me. Prevents me getting too tied up in any one ecosystem so that I can jump ship if Apple start releasing duds again.