I have written some with Scrivener and I like it... maybe better than this because Scrivener seems less (re-)learning curve.
You can write all sorts of things with these, they offer better management of the task than Word.
I like Nisus Writer, but it's a word processor, not a novel writing software... Is there any difference? 
Yea these two programs help you organize your outline and notes. There's a kindle book on writing a novel with Scrivener.
I think I had a trial version of Scrivener, but I didn't use it much -- yet, I remain interested in the software.
Ah, I see. So: not the same task at all. Nisus is a direct competitor to Word; a text editor.