When Gutenberg was first available to be tested I hated it. Thought it clumsy and felt it created a non-fluid authorship process. And it was bad. I knew Gutenberg would mature and it has. My reservations now center around compatibility with custom fields and existing plugins. I quite like Gutenberg now though it is not be an appropriate editor for all types of content.

I still believe a full TinyMCE editor block must always be available in Gutenberg. Many authors prefer to use a single word processor style canvas compared to using multiple blocks to build a page. I hope Automatic keeps the Classic Editor block when WP 5 arrives.

Already a few of my clients have complained about the 'Squarespace' editor. They do not look forward to it becoming the default editor. I think they will be fine with it once they learn the shortcut keystrokes such as changing a paragraph block to an image block by typing \image as the first word.

The help documentation for Gutenberg needs a lot of work and the showcase website needs to concentrate on 'how to use' more than 'why we [WP] did this to you'.

A few of my thoughts on Gutenberg can be read here https://journalxtra.com/wordpress/wordpress-4-9-8-gutenberg/