I updated to windows 10 this weekend on my computer with windows 8.1 pro. The upgrade went pretty smoothly and was faster than I expected. I did a manual update using a link on the Microsoft web page. With the pro version I was able to set windows update to notify me, rather that to automatically download updates, via the group policy editor (gpedit) which was one of my major concerns (I don't like things downloading when I'm working or streaming video and using up my bandwidth).
Only problem so far is that my CAC reader will not work so I can't connect to my work web email server. I also had to turn off the feature of the search button that looks on the web, since it seemed to want to check the web over my computer for everything.
I'm also a bit irritated with the edge browser as it doesn't seem to let me open multiple instances of the browser from the icon. I had a web music player running (not a regular browser window, more like a pop-up window that has no menus) and wanted to check something on another site, but couldn't open another window. Right clicking the icon does nothing and left clicking it just makes the current window active. Clicking around on that window did nothing either since it was just a pop-up type window. I had to close the music player window and reopen the browser basically ending the music. With Internet explorer or google chrome I can just right click the icon on my shortcut bar to open another window. It also always opens on my main monitor rather that the second monitor I want it on regardless of where it was when I closed it and doesn't seem to remember the window size and shape of the previous session.
Overall I don't see much change from 8.1 other than moving a few things around. But the edge browser seems sub par.