I just upgraded to Windows 10 recently, and so far (for the most part) it's working great!
The only issue I have is that some windows won't focus and stay on top when I alt-tab to it or click it, like it did in all other versions of Windows.
For example: I have Chrome open on top, I alt-tab my music player (which is in a small window), and the music player goes in front, but when I click the Chrome in the back of the player, the player stays in front, covering parts of the screen. This happens to multiple programs I run.
Besides this issue, sometimes when I alt-tab to a program, it just doesn't even show up in-front of whatever other program I have currently on top.
Anyone else with these problems?