In my case
- my laptop is a dual boot Win 7 / Debian Linux machine. If it wasn't for the Linux-incompatible sound card, I wouldn't use Win7 on it at all.
- my wife's is a Win 7 machine
- my spare desktop is a Win 7 / Debian machine.
- each of my sons have a Win 8.x machine (one steadfastly refuses to connect to the Windows Store, so it hasn't been upgraded to Win8.1 yet). And you need Win 8.1 in order to upgrade to 10. I have to say, Win 8 is a royal p-i-t-a.
I'll upgrade mine first to see where the hiccups are. Once I bend that one to my will, the others will follow. And if I hate it, I'll restore back to Win7.
The rest of the PC's are either running XP or Debian, and will remain that way.