No, I'm RSutton, a newbie here at least. The only issue I've found occurs when you are exporting your Word compatible format file out to mobi or ePub production formats. The heading-derived indexing is lost. It may be because the conversion software can't easily import a regular Word file (2003, 2010, etc.,) and needs a '97 compatible format. ePubs have other format restrictions, too, but in an eBook a working Index/ToC is critical. So I do it the old-fashioned way, manually, using anchors on Chapter Headings and internal bookmarks to the chapters linked back to the ToC page. Takes a while, but it works. Of course, if you're just using your Word file to create pdfs, or sharing it in Word format, none of this matters.