Yes, I understand the difference between beta and final versions. Beta is where the bugs are supposed to be worked out, not final versions.
Even betas need to be stable. That is the problem here. You can't work bugs out if you can't get the OS to run right and manage the system resources.
You're still missing the point. By Beta phase II the base of the OS HAS to be stable.
It's not. This is the final beta before release and it should not be having these difficulties.