I started using the block editor a little while ago on main projects and for the most part have been finding it an enjoyable experience, despite my initial scepticism a year ago. I have been testing the various iterations in the form of the Gutenberg plugin, so what’s in the WP5.4 version is a bit of a blur right now. I will say though is, the UI demonstrated in the latest version of the GB Plugin will be a big big improvement when it gets rolled into WordPress.