I found that this option never worked for me. The only time I encountered conflicts was when writing something in a discussion page and have someone write something before I post my own.
In that case I would like to have the current version and add my own. But the interface seems to force me to choose between one of them.
What I normally do is go back, copy my text additions, and re-edit the page. The conflicts page merely gets in my way, as in the original interface I could have at least (in most cases) copied and edited the text within it.
Am I missing something?