[Ripplinger]

For my situation, the Calibre plugin was exactly what I needed. Originally I went with straight quotes because it was my first book I did and used MS Word and that really messed it up. It was just one less headache to deal with.

Now the book is really finished, all formatting and corrections already done in Sigil. Yes, it would have been easier to do had I thought of it before this point (such as with the Atlantis Word Processor), but having to do it now, after all else is done, I'll have to say that the Modify ePub plugin did an amazing job. It changed nothing else in the book except the quotes and ... to ellipses. I had to change a few of those back, but all in all, it really did an amazing job without changing anything else in the book, everything else was untouched.

Of course I'd love a way to have done it in Sigil first, but that wasn't an option.

Edit: Oops, I take part of that back. For words such as Tis, it used the incorrect apostrophe, it used ‘ instead of ’, but that will be an easy search and replace in Sigil to correct.