I have installed Gutenberg in several production sites where it is in use as the default editor. It works fine. The bloggers I've shown Gutenberg to immediately warm to it and see the advantages of it.

I am one of those who had doubts about GB initially but only because it ignored custom post meta.

If anyone has technical problems with Gutenberg they are very likely caused by 3rd party plugins or themes that are awaiting compatibility updates. The popular plugins like Yoast, WPML and Elementor, and themes like GeneratePress are getting the dev care needed to make them GB compatible.

At this stage in Gutenberg's development it is mature enough for production sites and I welcome its adoption in WP 5.0 at the end of this week.