I need to run Windows (7) two or three times a month so two of machines are dual-boot, taking the main one: One of the applications I have relies on a vpn connection and is extremely sensitive. Both the virus-scanner update and Windows update require the vpn to be deactivated. All this means that I have to fire Windows up a day before I need it to get those oh so important functions out of the way. Factor in that some updates have broken my machine and were automatically backed out (and re-installed, and backed out), and that Windows will sometimes meditate for an hour or three before getting its update lists and another hour or three before performing the updates I permitted - I spend far more time administering the beast than using it. The bug where Windows 7 says that the network cable has been pulled, the one where you have to remove the power cord for 20-30 minutes? Seen that.
Windows 10 requires you to install all updates, that would include the ones that put me into an update/back-out loop.
My laptop could possibly be a candidate for Windows 10. The vpn application does not work there anyway, and it goes into sleep-mode when I tell it to install the May updates. Yes - it waits so long for those updates that it gets bored and goes to sleep.