All their other updates done through Software Update use a very sophisticated binary diff setup using Colin Percival's bsdiff — the updater checks the current s

All their other updates done through Software Update use a very sophisticated binary diff setup using Colin Percival's bsdiff — the updater checks the current state of your filesystem, hashing the files covered by the update manifests, and downloads the smallest possible update. The only downside is that the "Checking for new software…" dialog takes fucking forever.