For those who don't want to read all of the details...
Basically everything from CPU to RAM to GPU is 2x - 3x higher performance than the RP4 from 2018.
Support hats will be available directly from RP for both PoE+ power (no need for external power on these!!) and, drumroll, for M.2 NVMe drives. Meaning you can really use this as a real computer like never before. Lack of native M.2 support was the killer of the RP4 generation.
An RP4 with NVMe would have made it a reasonable desktop system. Without it, it was hard to do anything requiring drive performance of any sort. With more than double the performance across the "board" and NVMe support, this is a very, very powerful workstation.
Active cooling is now semi-standard to accommodate all of this, too.
Now if only I could get one - I have a need for two of these right now..
The Linux / Windows approach gives you far more flexibility. MacOS is useless in a million scenarios. But when it is good, it's really good. The UI is still pretty crap, but things like patching they can do with a reliability no one else can. No matter how hard anyone tries, vertical integration of components means things like patching can be tested completely, not just spot checked.
After scouring countless sites and articles, only thing that could fully read the drives was UFS Explorer. $700 later and many, many crashes, we are starting to have a reliable process of recovering the data. We have to use UFS Explorer and recover as raw disk images. Then attach those raw images to new VMs manually. Then do a Windows recover to each one.