neilm

I bought an iMac Pro for the office last year — 10-core, 64GB/1TB, $7500 or so. It's used as a video editing/processing workstation. We also have a bunch of well-optioned regular 27" iMacs.

The reason to shell out the big bucks for the iMac Pro isn't just performance, it's endurance. The improved cooling system allows it to crank at full speed indefinitely, making it the tool of choice (other than the newer Mac Pro) for long duration jobs such as rendering, or video transcoding. The regular iMac doesn't have the thermal headroom and has to throttle back the processor clock speed for long jobs.

Due to the unchanged RAM slot location it seem obvious that the just-released 27" iMac — and there's one being delivered to our office today — can not have adopted the iMac Pro's upgraded cooling system. Whether Apple has made any other cooling system changes remains to be seen. I'm betting not, because otherwise they would have claimed improved cooling as a benefit — and they haven't.

However both the 10th gen processors and the newer video cards should be more efficient, possibly helping out with the thermal load. Offsetting that are the higher core counts.

We have two of these, one first release model at the office, one more recent at home (plus a couple of their 4K cousins). We’ve never seen burn-in problems on any of them. Brightness is set at a reasonable level. Occasional problem with waking from sleep on the newest display, although since it’s fixed by a reboot, it seems as likely to be a software issue at the host end. Never had a sleep crash, never seen flickering lines.

If we were seeing those connection/negotiation problems I’d be looking at alternative TB3 cables.

You've always been able to reduce translucency via Display in the Accessibility system preference.
I very much doubt Apple would have changed that.

Something I've noticed with the very compact SSD drives is that they can get quite hot during sustained writes.

For instance I have a 1TB Samsung T5 SSD that I use as an intermediate step for migrating a user from their old Mac to a new one. (This allows not having to take both Macs offline at the same time, as well as assuring a just-in-case backup.) The first step is to clone the old Mac to the SSD, which typically means a sustained write of two or three hundred GB.

The good news is that this goes really fast. The bad news is how hot the SSD gets in the process. The first time I noticed this at home I grabbed an aluminum saucepan lid from the kitchen and put it on top of the SSD to act as a heatsink. This actually worked very well. Since then I've taken another drive with a heavy aluminum case to use as the heatsink, which also does the job.

I'm guessing that even faster drives, such as the new T7, won't run any cooler than my T5.

I can well imagine a 23" iMac update. The current 21.5" display is a bit cramped by modern standards, but for home use a 27" iMac rather dominates its space. 23" would be Goldilocks' "just right" for the home, while with narrow bezels it need be no larger that today's 21.5"