I used yWriter for quite a while, and did the first draft of Sad Girl in it, but didn't like the feeling of doing later edits with it. Ended up going back to Word for the final edits.
But by the time I was ready to publish, I had switched to Linux as an operating system, and so was using OpenOffice. Remember that OpenOffice and LibreOffice are suites, just like MS Office. They all include a word processor, spreadsheet, presentation, and database package. OO and LO will both save to .doc format as well as .html, and their html format is usually cleaner than that of MS Word.
But what I found as I was working to self publish is that 98% of the helpful hints that are out there refer to PC or Mac operating systems, so I was having troubles figuring out how to do a few things in OO, so I ended up going back to Windows and Word. It's just more comfortable.