Reason No. 2 to prefer plain text to .docx for legal work:

Automation. Scripting and automating plain text documents is much easier and more flexible than automating .docx binaries. And there are far more tools to work with.

@ciaran I’ve found that the ability to combine Word’s (admittedly idiosyncratic and cut-down) implementation of regular expressions with search for specific styles and/or direct character or paragraph formatting, and to combine these in VBA scripts, can produce very useful and surprisingly powerful solutions. If I were starting from scratch, knowing what I know now, I might have taken a different approach, but I’m not at all sure I would have done.

@artkavanagh I don’t disagree. Word is quite powerful, and between VBA and some of the over-the-counter plugins you can buy for the Windows version, there’s quite a lot you can do. But the tools for manipulating plain text are more plentiful, diverse, and potentially even more flexible than those for Word.