I just upgraded my desktop PC to Windows 10. I hadn't actually intended to do that just yet, but I found out the hard way that when you click on "Upgrade Later," that doesn't mean, as I had assumed, "download the files and be ready to upgrade later, whenever I feel like telling you to," but rather, "you must now schedule your upgrade for sometime in the next few days, and then you will be irrevocably committed to it, bwahahaha!" Oh, well. Except for the fact that I was sure I'd scheduled it for 2 AM and it instead happened at 8 AM when I was actually trying to use the computer, it seems to have gone remarkably smoothly. And I no longer need those third-party apps I had installed on Windows 8 to bring the Start menu back and enable me to use the "modern GUI" apps in resizable windows.
All of which mostly just means that I'm still waiting nervously to find out which part of it I'm going to hate. But, hey, so far, so good!