Thank you for the review. I would say that the main advantage of SingleFile over SingleFileZ is that pages saved with SingleFile do not require JavaScript to be enabled in order to be displayed. In other words, if you want to save your pages as "pure" HTML files, use SingleFile. If you prefer to save them as zip files disguised as HTML pages, use SingleFileZ.

Note that SingleFile allows you to edit the page with the editor you refer to (I'm glad you like it). SingleFileZ cannot do this because it is more complicated to implement.

EDIT: Thank you!