I'm not a designer or an expert in UX, but as someone who uses the editor on a regular basis, I don't really like the new layout with sections on the left and settings on the right. Here's why:
Most laptop users are using the left side of the screen, as most applications like operating systems and others are designed that way. It's also natural because most people write from left to right (LTR).
By doubling the space for the editor, customers get a tablet view of the website. This forces you to switch to full-screen mode every time you make a change, which was not significant in the previous version.
It's also quite annoying to have to move your head and mouse around so often, and writing in this layout also feels unnatural to me.
It would be great if the design team could consider bringing back the old layout or at least providing an option for customers to choose between these two layouts.