A few thoughts...
The high speed/no bottlenecks nvme SSD could be a game changer - I tried a large samsung SSD in PS4pro and it made negligable difference because the console was bottlenecked by CPU etc. Custom hardware to alleviate those bottlenecks is a big step forward, but one that has no equivalent in PCs right now.
Xbox series X has some bottleneck reduction, but only PCI-E 3 perofrmance levels (2.5-3GBps).
Games developers, for the most part will be developing on PC, which will lack any of this bottleneck reduction. Sure, high clock, high core count CPUs with high memory bandwidth/cache may offset this somewhat, but most devs will be targetting consumer SSD level hardware (ie. SATA 600 MB/s) because of available hardware. I suspect the "game changer" aspect will only apply to first party titles as a result.
MS showed the tech being used for fast game switching, which I think is a more tangible use of nvme performance right now. Indeed, MS presentation seemed a bit more grounded in reality than Sony did. BTW, I play more-or-less equally on Sony/MS/Switch (and to a lesser degree PC), so no axe to grind.
We've heard about 3D audio hardware from different companies for nearly as long as PC 3D accelerators have been available. Yep, I had an aureal A3D card alonside my original 3DFX! Each time (Aureal, Creative, Nvidia nforce, AMD trueaudio etc) it has promised the world, and eventually fallen by the wayside due to practical issues and, ultimately dev/player apathy. Maybe Sony will be the ones to push it through, but with only headphone support at the moment, I remain sceptical. The consumer hifi/AV market has standardised on Dolby Atmos / DTS:X, and I suspect anything else would be a tough sell. But, kudos to Sony for trying something new
Both companies are already "apologising" for their small storage (ie. no larger than current gen consoles). Does not bode well. Both my Xbox and PS4 have (mostly full) 4TB drives, and with backwards compatibility, that's only going to rise. Fortunately backwards compatible games can be run from USB.
Also, both are apologising for "only" 16GB by claiming that data can be read in "instantaneously" to remove the need for stale data in RAM. Sounds great, but also sounds like devs will need to change the way they design games. I suspect if one of them had bitten the bullet and gone 32GB, this would be a non-conversation. Both consoles mention 8K in specs, but don't talk about it - 16GB (13GB usabale) will be far too paltry for that - Control (current gen) uses 18.5GB of video memory alone for ray traced 8k.
However, for the price - I can't wait!