I saw very big user experience issue that I encountered myself. When I click "Edit" tab on any page and have visual editor panel opened and I want to go back to reading, I can't. I couldn't find a way to go back (except browser's Back button, of course) and this annoyed me very much. There should be a Cancel button or anything that clearly states for canceling the action of editing, but it does not exist (if it does, this issue proves you it's almost impossible to find it). The only way I figured out to go back is to click "Read" next to "Edit" again, but this is IMHO very very unintuitive.

As of that I suggest adding a Cancel button. Maybe on the right/left of "Publish Changes"? Or maybe an "x" icon on the left of help?