We do apologize for the long delay. You can read about that in detail here:
That said, the public betas are very stable, and the internal betas are also very stable.
That said, we have a "Known issues" post, that summarize many of the current and fixed issues that we do know about.
This isn't comprehensive, but covers most of the bigger issues.
You should be okay using either version, but I would personally recommend the latest internal beta.
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