Been on 9.0.10 until yesterday which was fine on the whole.
Skipped 9.0.20 as it audio glitched like an audio glitchy thing here all the time.
Now trying 9.0.30.
Seems to work well overall. The audio glitching seems to be cured.
BUT, had a 9 hour session today during which Cubase performed stably, but I noticed a slowing of the graphics performance through the day til eventually things like FabFilter ProQ2 were running at a slow enough frame rate to ruin the experience.
Closed Cubase and re-opened it with the same job. Did not reboot. Graphics back to smooth and full speed again.
So there is some time-dependent problem with graphics in 9.0.30 which needs to be fixed.
Overall though from my perspective, this is a pretty good release.