I might mention that there is a
Go back to Windows 7/8 button in
Settings > Update & Security > Recovery.
This feature will work for a full month after updating for as long as you don't delete the
Windows.old folder.

I will stick to Windows 7 for a long while. If it works, don't fix it. I am worried about Microsoft doing something stupid and making the OS inoperable after an update. Also, tons of privacy issues apparently. It is almost like giving the keys of your PC to Microsoft.
Try seeing Windows 10 not as a "fix" but as an improvement over what was already good. There's a LOT of things that are better such as bootup times being insanely fast no matter what drive you're using and game performance being quite a lot better. Even older games seem to gain several few FPS compared to Windows 7.
The privacy issues aren't as bad as people make it out to be, it isn't worse than that of say Google, Apple or Youtube. The difference is that Microsoft is being fairly open about it and gives you checkboxes to turn everything off. Right after updating it'll ask you to set a few settings. Make sure to click "Customize settings" instead of "Use Express Settings" and turn off anything that you feel is bad for your privacy. Even after that you can also change whatever you'd like in the
Settings-menu!

I completely agree, Windows 7 (In my opinion) is the most stable build of Windows. Windows 8 and 8.1 was a complete disaster so I'll stick to Windows 7 until Microsoft forces me to upgrade.
How come? I know Windows 8 had a few issues for the first few weeks but they were all fixed pretty quickly. Did you actually give Win 8 a try and for how long? Because it's not really that bad once you actually use it.. Like sure the whole Metro thing can be debated but if you disregard that one detail 8 was a significant improvement over Windows 7 in terms of details and under-the-hood; The whole kernel is much faster and better making it faster and more responsive than Windows 7 ever was, the Task Manager is reworked and much better and more useful, the progress box that comes up when copying or moving files shows is way better and overall the experience when copying or moving files is much much better (clicking "more info" actually shows more information!), multi-monitor support is another massive improvement too, for example.
All of these well-appreciated improvements Windows 8 brought has been carried over to Windows 10 whilst the things that Windows 8 was criticized for has been resolved and thus I would personally say Windows 10 is the best of both worlds between Windows 7 and Windows 8.
Well, that's just my thoughts anyhow, feel free to disagree but I'm sure updating won't suddenly make your PC explode. It's better than Windows 8 but is similar enough under the hood that essentially anything that worked with Windows 8.1 should work fine in Windows 10 as well!