One of the biggest community and customer benefits of UUP is the reduction you’ll see in download size on PCs. We have converged technologies in our build and publishing systems to enable differential downloads for all devices built on the Mobile and PC OS. A differential download package contains only the changes that have been made since the last time you updated your device, rather than a full build. As we rollout UUP, this will eventually be impactful for PCs where users can expect their download size to decrease by approximately 35% when going from one major update of Windows to another. We’re working on this now with the goal of supporting this for feature updates after the Windows 10 Creators Update; Insiders will see this sooner.
Not earth-shattering or anything, but still a nice improvement.