It feels like a step backward in editing. I lose the text editing capabilities of TinyMCE, and it seems to take more effort, not less to complete a post.
Also, as Divi user, Divi had to create a work-around in order to get the builder’s back end to still function.
Overall – it feels clumsy and not intuitive.
That said, I’m not giving up on it just yet and fortunately, Divi has provided a convenient “switch” to turn it on and off – but it will be quite a while before it becomes my editor of choice.