I'm excited for the iMac Pro. It's definitely Apple's first interesting Mac since the MacBook Air ten years ago. There is a mark-up though. With the introduction of Core i9, 8-core Xeon Gold will start at well under $1,000. The "Radeon Pro" is just a branding exercise - make no mistake, this is not a Pro GPU. Indeed, that's a misnomer as there are no separate Pro drivers for macOS. It's the same deal with the MacBook Pro's Radeon Pro. It's just a branding thing, the Radeon Pro 460 in MacBook Pro is no different from the Radeon RX 460 in terms of both silicon and drivers. Indeed, it's actually lower clocked.
I'm not too concerned about the thermals and noise. While 18-core sounds like a lot of cores, they'll almost certainly use a lower-clocked part like the Xeon Gold 6140. That'd be 135W TDP. Meanwhile, the Vega GPU is also heavily underclocked from the Vega Frontier Edition, let alone RX Vega. Given that the Frontier Edition is clocked +200 MHz at 250W, it's fair to say that the Vega in iMac Pro will come in at around 150W TDP.
That's less than 350W total. Meanwhile, the current iMacs have a total TDP in the 200W-250W range.
So, sure, it's going to run a bit hotter than the regular iMac (which run too hot, in my opinion), it's unlikely to be a major issue.
As for those who require expandability, configurability and reparability, the new Mac Pro is coming next year. Or rationally, just buy one of the many stunning options on the Windows and Linux side of the fence :)
I wrote about this very topic a few days ago - https://steemdb.com/tech/@liberosist/thoughts-on-apple-s-imac-pro
Cool thanks for your perspective. I will check out your post :)