Hopefully they get their shit together fast. Tons of people have been having issues with the new update feature that also allows Windows to update your GPU drivers. Twice now I've booted up with old GPU drivers because Windows was automatically updating to the latest non-beta drivers, whereas Nvidia's only Windows 10 drivers were in beta up until yesterday. I don't like the idea of Windows updating my GPU drivers without my knowledge, especially if it's going to interfere with the ability to use beta drivers. Seems like a simple fix, but I don't know if it's actually been fixed yet.
They also desperately need to clean up the Windows App Store if they plan on utilizing it all this time around. Thing's a bigger disaster than the Google Play Store.
And the Xbox streaming feature has actually gotten worse with the updates. Now it has this feature that automatically turns off streaming if you tab out of the program when it's in fullscreen, and there's no borderless windowed option. There's also three quality settings, and only low and medium do anything. The high setting doesn't seem to do anything at all, making the quality difference between the stream and the original Xbox One footage very noticeable.
And finally, a small issue that I don't understand the existence of. That option that's supposed to change your color scheme based on your wallpaper doesn't work if it's a slideshow. This wasn't an issue in Windows 8.
Edit: Not sure why you would bother with a clean install. You haven't come up with a better solution to something than the people who created that OS. Just install like normal, and delete windows.old