Windows 10 Pro is pretty decent. There are a few questionable decisions (like app suggestions for Candy Crush etc.) but they're mostly optical annoyances or tiny background problems that can be fixed quickly.
What I always do when I install Windows 10 is use Winaero Tweaker afterwards and tick all the obvious boxes: Disable uploading updates to others (because I want my bandwidth for myself), Disable Telemetry, Disable Cortana, Disable Start Menu Suggestions.
I also install the subsystem for Linux and Winaero Tweaker can then put a right-click link to bash into the menus.
With that, I can use my Linux tools of choice (like grep, find and ssh) while still having access to Photoshop and Illustrator.
I would love to switch to Linux completely, but that's impossible in an advertising agency. I have access to it on our beefy corporate server, so that's fine for me - I'm not forgetting the skills from the Linux world. 😀
Regarding Windows 7: I don't use it on at all on my systems anymore. There's just no need for it. Everything that runs on 7 will also run on 10. I have a few XP and 98SE machines because some software depends on these specific versions. That's not the case for 7.
Maybe there will be a tweak like the PosReady hack for XP that gave us updates up until the start of this year if the demand is there.