Basically any desktop machine with a high end desktop processor and some decent graphics card. With the iMac pro you are even limited to buying RAM with the machine. And with a desktop, you get to choose your graphics card.
> With the iMac pro you are even limited to buying RAM with the machine.
You can upgrade the RAM after purchase by going to an authorized repair store, or by reading a couple of iFixit guides if you're fine with doing it "unofficially".
Well, nice that it isn't soldered, but the machine is glued shut. So any work on the inside is getting expensive. When I bought my iMac, the dealer charged me close to $300 for a disk exchange.
That is certainly something else one could critisize, though with the combination with Metal2, the AMD graphic cards seem to be a great alternative. Yet, they offer way more choices than you have when configuring an iMac or even Mac Pro (but with that, probably generic AMD graphic cards would probably work)
