Lately several customers have asked if they should accept the free upgrade to Windows 10 being offered (rather insistently) by Microsoft. I would wait until all the bugs are worked out.
I have seen some minor and not so minor settings changes after operating system upgrades. For example, one customer updated her laptop from Windows 8 to Windows 10 on her own and, upon restart, her touch screen and her USB ports stopped working. It’s possible the drivers (software) for these devices wasn’t compatible with Windows 10. The bottom line is that when she restored the computer to Windows 8, the devices started working again.
In the past we have seen issues when updating from Windows 8 to Windows 8.1, such as printers being uninstalled. I don’t know if this will happen with the Windows 10 upgrade, but it is certainly a more radical upgrade than going from 8 to 8.1, so it’s entirely possible there will be glitches and settings changes that will be, to say the least, inconvenient.
The bottom line is that there’s no compelling reason to upgrade. Windows 8.1 is a good solid operating system, and if you have it configured correctly, it should be as easy to use as Windows 7. Let someone else be Microsoft’s guinea pig. You can always revisit the upgrade question in six months.