I am currently testing out AppX for a customer Appx is fairly easy for small applications such as Adobe Reader and so on.
does anyone have any experience in packing larg
Converting the packages is now much easier with the new free Express edition from Advanced Installer, developed in partnership with Microsoft.
It has a GUI that allows for advanced customization of the APPX packages, without requiring you to have knowledge about the internals package schemas.
If you have any questions about it, let me know, would love to help.
Disclaimer: I work on the team that builds Advanced Installer.