[DNSB]

Personally my vote if for creating the original document in Word/LO Writer using styles and then importing the file into Sigil or calibre. Neither Sigil or calibre ebook editor are really designed for writing but both work well for cleaning up an existing document.

PageEdit is a lot better than Sigil's old BookView WYSIWYG editor in terms of not creating garbage code but not something I would want to use to create a book.