Earlier quoted context omitted.
I disagree on the zip. dmg used to be the preferred format for reasons I never entirely fully understood, but that ship has sailed, and I think for the better. Zip is much more convenient. You can, of course, sign the app within the zip.
You can sign the app within the zip, true. The advantage of using a dmg is to control the presentation, which seems like a strong desire for this particular product. Downloading a file named "latest.zip" that had an unsigned binary in it was by far the worst part of the excellently designed experience of installing the software. Apparently the iTunes link thing is a bug https://twitter.com/jschloss/status/39778394974…
The nifty "presentation" adds a several needless steps and pitfalls to running an application:
• Mounting and verification of DMG is slow (Zip CRC and Developer ID signatures give you verification too).
• "Nothing happens" after clicking DMG — user has to find DMG mount on a cluttered desktop.
• Clicking app icon in the DMG window is tempting, but generally it's a no-no (some apps don't mind, but some ask to be moved to Applications, and some throw "error -13 read only volume" kind of errors).
• User is expected to copy the app to Applications folder, with instructions given in form of non-localizable non-accessible text-in-image, and it's trickier when sidebar with shortcut to Applications folder is hidden (and remember "Applications" folder name is localized and sounds nothing like it in many languages).
• User has to unmount and delete the DMG, but that gives non-obvious behavior when the app is running off the DMG.
• It gets super confusing when user has pinned app in the Dock while it was running off the DMG