All good here.
I've installed it on 4 laptops and a tablet. Two laptops were upgraded from Windows 7 (the oldest is 5 years old), and two from Windows 8.1 (both came with Windows 8 originally). The tablet was built for Windows 8.1.
All are running fine, no hardware or software compatibility issues, no loss of data or applications, and no dramas with any of the upgrades. All are running at least as well as they were before, and the slowest machine now boots noticeably faster than it used to.
Two thumbs up from me.
