Not much, but it can be a trick to install. I have 3 PCs, all 3 failed the update multiple times. I had to do this:
1. Go into "C:\Windows\SoftwareDistribution\Download" and delete everything in that folder.
2. Now, run the command prompt as an administrator. Type in "wuauclt.exe /updatenow".
Then go here: Windows 10
That's the link to the Upgrade Tool.
Works now, on 2 of 3.
The last PC is constantly searching for updates. Still figuring that one out.
It's better than 8.1 Metro, but not as good as Win7. Just my 2 cents. The search bar at the bottom next to the plain start button is rather large. It has this minimalist unflashy feel with the icons. Basically looks like an old windows phone.