Just upgraded from 7 yesterday. Haven't found anything that doesn't work - but I never play DVD's anyway. Sure, it wants to connect you to the Cloud and share lots of stuff, but it gives you the option as installing to customize and turn off those things. They've actually done a pretty good job of notifying you as to what will be shared, when, and what to do if you don't want that to happen.
Since my machine is fast, but older, I don't have the fancies - no touchscreen, microphone, camera, etc. so I can't say it is a big improvement from Win 7, but it is on the plus side, and looks to be a keeper.