Do not want to save the whole menu each time you need to edit one or two elements of it?
How often do you copy code snippets from another websites? What do you like the most – code with the tabs or with a lot of spaces? Do you see the difference?
I think that default WordPress fullscreen editor is very easy to use. But there is one problem – when you want to preview your post on the blog, you need to switch off the fullscreen mode each time. It is very painful.
It is very useful when you work with a lot of similar posts. So, when you copy a post, you don’t have to enter all metadata, taxonomies etc. each time manually.
How to remove default metaboxes, how to create your own custom metabox on the fly. The complete tutorial.