Sigil has one less advantage now that Kovid implemented saved searches into the calibre editor. And the calibre editor is faster, has proper support for revision control, global undo and other goodies...
Sigil is no less useful than it used to be, of course. But at this point, the only
advantages over calibre editor that I can think of are the spellcheck and clips, both of which will be coming to calibre at some point. And Book View, which I hope no one here relies on.
