As this is a build from the "release" branch of Redstone 4 development, don't expect there to be many, if any new features in the build. Indeed that is the case, with the only significant change being to Windows Update - From rs4 onwards, Windows Update will keep a PC that's on mains power awake for up to 2 hours when not being used in order to "allow Windows Update more opportunity to succeed".

Other than that, there's a whole bunch of fixes, of which the most important is another Windows Update related fix - essentially Windows update will now no longer "pause" for up to 90 minutes while at the 88% stage of installing a new build. Here's the full release notes from Microsoft.