Can you provide some more specific examples?

Examples of articles where I need to use both? That would be any article where I'm trying to manipulate citations (move/add/append/improve) or with templates; as well as doing some general editing.

Example of what I want? A button saying "View this in the old editor", and clicking on that gets you the same article, including any changes you made, in the old editor. Alternately, you could display the same button in the preview mode when you're viewing the article

Another editor adds:
If you want to switch (say you started in Visual, but you want to switch to source to get something fancy working), you have to either discard your changes or save a partial edit in visual and create a second edit in source. What I want to see is a means of switching between the two at will within the same edit. Wordpress does something similar where you can type up a blog post to switch between visual rendering and HTML source using tabs surrounding the edit window. You can switch between visual and HTML at will and each will be updated. I want to see the same thing with the Wikipedia VisualEditor. -Thunderforge (talk) 21:32, 6 July 2013 (UTC)

AND

They don't necessarily have to both be visible at the same time (in fact, that might be somewhat confusing and perhaps wouldn't work well on mobile devices and tablets if the VisualEditor is going to be used there). But I would like some way to switch between the two without having to discard an edit. Again, the tabs on the edit window that Wordpress uses are one excellent way to do this: they allow the edit space to be swapped out, providing a compact way to easily switch. A picture of it can be found here. -Thunderforge (talk) 21:40, 6 July 2013 (UTC)

Oops - just realized there was an external link in his comments.

The picture he mentions in his last sentence can be found here:
http://en.support.files.wordpress.com/2009/07/visual_editor2.png?w=688

This is the same as bug 47779

• This bug has been marked as a duplicate of bug 47779 ***