Microsoft has released a new build for Windows Insiders, build 14915. Lots of fixes this round (including my #1 issue – power button broken on Start Menu! Always had to right click to get it…). The app and update delivery has been optimized, as well.
Starting today, Windows Insiders that have Delivery Optimization enabled will be able to download new Insider Preview builds, OS updates, and app updates from other PCs on their local network as well as from other PCs on the Internet. We introduced Delivery Optimization with the Windows 10 November Update giving users the ability to get updates from PCs on a local network and are now enabling the ability to get updates from PCs on the Internet.