Beta 1 is a total disaster (unfortunately):

My theme's meta box in the side in not showing but I have a plugin that shows up and works up perfectly at the bottom. Also, the 5.0 beta 1 experience is miles apart from a site using WP 4.9 and Gut. 4.1 (just got updated).

Some examples:
With WP 4,9/Gut 4.1 I can:

-Disable Gutenberg with a simple filter.

- The Classic Editor Block, SHOWS custom buttons in the toolbar placed by themes and plugins (extremely important for shortcodes for example).

- I can resize the width of the editor from the pathetic 600+ pixels.

- Again, no issues with ACF and ALL types of Meta Boxes.

All these things mentioned above (4 of them) DO NOT work with either the WP 5.0 beta1 (official), or by using the WP beta testing plugin. And all these major issues with just 10/15 minutes of testing.

Gut. 4.1 with WP 4.9 has changes that affect the custom blocks made with ACF 5.8beta1 too, but those are minor which will and can by fixed by Elliot (the ACF developer). But things with WP 5.0 are really messed up, it’s like they rolled the Guten. development all the way back to 6 months or so… simply said, they did not just “embed” the Gutenberg plugin into the core, they “mutated” parts of it for whatever reason. And wow, fresh WP installation 43.2 MB… more than doubled from the previous installation…

I have no idea how this is going to be released in 26 days.... if it is, there is no way I'm updating anything unless things work at the very least as WP 4.9 with the Gut. 4.1 plugin...

What happened to quality control here? Months of testing and making things work with Gutenberg will be lost if this beta is the roadmap to the actual version release. I finally had such high hopes for this thing.