One of my main clients has insisted that we use Microsoft Word for project document collaboration rather than my strongly preferred Google Docs. But of course the client is always right, so I'm adapting.
But tonight I spent an hour longer than I needed to spend editing a document that required substantial modifications. Word on Mac OS X just seems to lose its mind from time to time. I lost substantial work three different times when all of the menus in Word — dropdowns and ribbon-based — just started showing blank contents. All other apps running at the time were fine. I'd try Command-S to save a document and get an absolutely blank dialog box in the middle of the screen. It was just plain weird.
On other occasions, text entry slowed to an absolute crawl. I'd be typing 5-10 words ahead of what was displaying on the screen while the disk thrashed.
I've been avoiding using MS Office products as much as possible for the past several years and now I understand why. They just don't work reliably.