Reduced Metro/desktop whiplash
In Windows 8.1, if you’re on the desktop and you double-click on a picture file, like a GIF or a TIF, you’re tossed into Metro hell, with the Metro Photo app taking over. If you double-click on a media file like an MP3 or MP4, up springs the Metro Video app -- which is the last thing you probably wanted.
The Update fixes those problems: Under Update 1, your pics open in Windows Photo Viewer; your media opens in Windows Media Player. Those aren’t great choices, but they’ll do until you can install third-party programs worthy of your desktop.
One throwback: PDFs still open in the %$#@! Metro Reader.