There have been some issues with power management, load distribution and stability. A quick googling will show you more. Regarding the other point: run lscpu a

There have been some issues with power management, load distribution and stability. A quick googling will show you more. Regarding the other point: run lscpu and compare enabled mitigations on Zen3 and M2. We still need a proper analysis to figure out which ones must be enabled on M2.