However...
Yesterday I was working on a simple document. My need was for a two-column document in which certain paragraphs had a column-wide border at the top to separate sections of the text.
First off, I realized that Nisus could not add borders to paragraphs. Ack! So, I figured using a table could be a workaround, with each section of content in a separate cell, each cell with a top border. Sure, this meant no wrapping to the next column, but I was going to at least give it a shot.
So, I drew a table with four cells and inserted it at the beginning of the first column, above what I had already typed. When I would drag existing copy to a cell, the remaining copy would slide upwards... BEHIND the table (and thus invisible). I then had to grab the table and drag it upwards (though it had nowhere to go, so it stayed put) to make the text beneath slide back down where I could see it. This would happen every time I would drag copy into a table cell.
Then, in moving copy to the third cell, Nisus crashed, i.e., "unexpectedly quit." It's been a while since I've seen an app do that.
I then went to my Office 2004 Test Drive, fired up Word, and tried the same thing. Just as with v.X (the last version I had access to), I was able to do what I wanted just fine. And with a previewing Font menu, no less.

(I generally save docs from Word in RTF. I viewed the file I created with Word in Nisus and Pages, and the paragraph-borders were gone. Is this something that straight RTF just can't do? Is Word using some Word-only RTF encoding?)
This is not an attempt to bust Nisus' chops. I really wanted to like it, and I was ready to buy a license. However, given the problems accomplishing the simple tasks I wanted, I can't really justify paying the US$70.
Granted, I'm in sort of a special situation. Via my job, I can get Office 2004 Pro for $199. Ergo, the extra $129 doesn't feel like that much more to spend considering I get the whole Office suite plus Virtual PC. If I were stuck paying the US$400 retail price, I'd probably be working harder to stick with Nisus.

(As for OpenOffice.org... I've considred it, but spending hours in a clunky X11 app isn't my ideal way to use the Mac OS. There's NeoOffice/J, I know, but I hear it's poky, even on a dual G5.)
Anyway, I relay this simply to make you guys aware of a possible bug, and to give you an idea of the kinds of things that would make a user choose your competitor's product. Nisus is the best Word-alternative I've seen on the Mac, and I want to see it continue to improve. Still, when it comes down to it, I can't see paying for it as-is.
And if I'm just doing something wrong in Nisus, please let me know.