Fleeing Microsoft Word, and wary of proprietary file formats, I started using Nisus Writer Express in 2005. Years later I switched to Nisus Writer Pro. It's improved along the way, but import/export remains a real problem. Today I tried using NWP to do a yearly solstice letter. It did a nice job formatting the letter, it even let me create hyperlinks.
When I went to export as HTML however, all I got was text. The images were attached in a subfolder, but not referenced in the HTML. PDF export gave me the images, but no hyperlinks.
I had to dump the HTML ouput text into Word 2007 (Windows, more's the pain) and recreate the letter from the source images. How humiliating.
Nisus Writer Pro is a wonderful product, but they've been stuck for years when it comes to import/export tools. I really need decent HTML export.
It's time for me to try iWork. Then I'll have a really tough choice -- the unreliability of Microsoft Office or the data lock of iWork. Neither choice appeals.
Update: iWork doesn't export as HTML at all. So in this regard it has no advantage over Nisus. I'll wait and see what the expected 2011 version of Pages will include.