> Has anyone examined its use as an OS volume, compared to today's leading SSD's?

Late last year I switched from a 1.5tb Optane 905P to a 4tb WD Blue SN5000 NVMe drive in a gaming machine and saw improved load times, which makes sense given the read and write speeds are ~double. No observable difference otherwise.

I'm sure that's not the use case you were looking for. I could probably tease out the difference in latency with benchmarks but that's not how I use the computer.

The 905P is now in service as an SSD cache for a large media server and that came with a big performance boost but the baseline I'm comparing to is just spinning drives.