I revert to UI2 because

… I can’t stand those fake floating panels, and the nonsense padding of the UI. If you want to create real floating panels (which is done everywhere with rounded corners and drop shadows, like… Photoshop) that’s fine for me. I will use it. But when I’m working on my laptop, this UI3 gadget is narrowing my working space too much.

You can switch back to the previous design. In order to do this, from inside a design file, open the help menu (‘?’ icon) and click Go back to previous UI. If you decide to switch back later, you can come back to this menu and try out the red…